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Hexagonal boron nitride (hBN) has emerged as a promising protection layer for dielectric integration in the next-generation large-scale integrated electronics. Although numerous efforts have been devoted to growing single-crystal hBN film, wafer-scale ultraflat hBN has still not been achieved. Here, we report the epitaxial growth of 4 in. ultraflat single-crystal hBN on Cu 0.8 Ni 0.2 (111)/sapphire wafers. The strong coupling between hBN and Cu 0.8 Ni 0.2 (111) suppresses the formation of wrinkles and ensures the seamless stitching of parallelly aligned hBN domains, resulting in an ultraflat single-crystal hBN film on a wafer scale. Using the ultraflat hBN as a protective layer, we integrate the wafer-scale ultrathin high-κ dielectrics onto two-dimensional (2D) materials with a damage-free interface. The obtained hBN/HfO 2 composite dielectric exhibits an ultralow current leakage (2.36 × 10 -6  A cm -2 ) and an ultrathin equivalent oxide thickness of 0.52 nm, which meets the targets of the International Roadmap for Devices and Systems. Our findings pave the way to the synthesis of ultraflat 2D materials and integration of future 2D electronics., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Metal conversion processes have been instrumental in advancing semiconductor technology by facilitating the growth of thin-film semiconductors, including metal oxides and sulfides. These processes, widely used in the industry, enhance the semiconductor manufacturing efficiency and scalability, offering convenience, large-area fabrication suitability, and high throughput. Furthermore, their application to emerging two-dimensional (2D) semiconductors shows promise in addressing spatial control and layer number control challenges. In this work, we designed a multi-step metal conversion process for 2D materials to synthesize a high-quality and ultrauniform film. PtSe 2 is introduced to utilize its wide-band-gap tunability, which exhibits both semiconductor and metallic properties. Our multi-step-grown PtSe 2 film shows extremely low roughness ( R a = 0.107 nm) and improved interlayer quality compared to the single-step PtSe 2 film. Additionally, we explored the growth mechanism of the metal conversion process and how the multi-step method contributes to the thickness uniformity of the film. We demonstrated a thin PtSe 2 channel field-effect transistor (FET) array with p-type behavior with a maximum on/off ratio ∼10 3 . The FET fabricated by the MoS 2 channel with the semimetallic multi-step PtSe 2 electrode shows an enhanced performance in mobility and contact resistance compared to the conventional single-step PtSe 2 electrode FET.

Conventional Si-based physically unclonable functions (PUFs) take advantage of the unique variations in the fabrication processes. However, these PUFs are hindered by limited entropy sources and susceptibility to noise interference. Here we present a memristive device based on wafer-scale (2-in.) two-dimensional (2D) hafnium disulfide (HfS 2 ) grown by molecular beam epitaxy (MBE). The polycrystalline HfS 2 thin film can offer enhanced entropy sources for PUF applications, such as lattice defects, which can facilitate the random formation of conductive filaments and result in significant device-to-device (D2D) variations. Our proposed PUF design seamlessly integrates two distinct operating modes within a single circuit module. First, a reconfigurable and highly secure mode 1, and second, an ultrareliable mode 2, both with near-ideal Entropy (∼1.0), normalized Hamming distance (∼0.5) and correlation coefficient (∼0.0). Additionally, a predictive Fourier regression model further confirms the unpredictable nature of our dual-mode PUF, with an average prediction accuracy of ∼50%.

Memristive crossbar arrays (MCAs) offer parallel data storage and processing for energy-efficient neuromorphic computing. However, most wafer-scale MCAs that are compatible with complementary metal-oxide-semiconductor (CMOS) technology still suffer from substantially larger energy consumption than biological synapses, due to the slow kinetics of forming conductive paths inside the memristive units. Here we report wafer-scale Ag 2 S-based MCAs realized using CMOS-compatible processes at temperatures below 160 °C. Ag 2 S electrolytes supply highly mobile Ag + ions, and provide the Ag/Ag 2 S interface with low silver nucleation barrier to form silver filaments at low energy costs. By further enhancing Ag + migration in Ag 2 S electrolytes via microstructure modulation, the integrated memristors exhibit a record low threshold of approximately - 0.1 V, and demonstrate ultra-low switching-energies reaching femtojoule values as observed in biological synapses. The low-temperature process also enables MCA integration on polyimide substrates for applications in flexible electronics. Moreover, the intrinsic nonidealities of the memristive units for deep learning can be compensated by employing an advanced training algorithm. An impressive accuracy of 92.6% in image recognition simulations is demonstrated with the MCAs after the compensation. The demonstrated MCAs provide a promising device option for neuromorphic computing with ultra-high energy-efficiency., Competing Interests: Declarations. Conflict of interest: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024. The Author(s).)

Atomic chalcogen vacancy is the most commonly observed defect category in two dimensional (2D) transition-metal dichalcogenides, which can be detrimental to the intrinsic properties and device performance. Here a low-defect density, high-uniform, wafer-scale single crystal epitaxial technology by in situ oxygen-incorporated "growth-repair" strategy is reported. For the first time, the oxygen-repairing efficiency on MoS 2 monolayers at atomic scale is quantitatively evaluated. The sulfur defect density is greatly reduced from (2.71 ± 0.65) × 10 13 down to (4.28 ± 0.27) × 10 12 cm -2 , which is one order of magnitude lower than reported as-grown MoS 2 . Such prominent defect deduction is owing to the kinetically more favorable configuration of oxygen substitution and an increase in sulfur vacancy formation energy around oxygen-incorporated sites by the first-principle calculations. Furthermore, the sulfur vacancies induced donor defect states is largely eliminated confirmed by quenched defect-related emission. The devices exhibit improved carrier mobility by more than three times up to 65.2 cm 2 V -1 s -1 and lower Schottky barrier height reduced by half (less than 20 meV), originating from the suppressed Fermi-level pinning effect from disorder-induced gap state. The work provides an effective route toward engineering the intrinsic defect density and electronic states through modulating synthesis kinetics of 2D materials., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

This paper presents an integrated passive device (IPD) structure based on fan-out wafer-level packaging (FOWLP) for the front end of frequency-modulated continuous wave (FMCW) radar systems, focusing on enhancing the integration efficiency and performance of large passive components like antennas. Additionally, a new metric is introduced to assess this structure's effect on the average noise figure in FMCW systems. Using this metric as a loss function, we apply the support vector machine (SVM) for electromagnetic simulation and the genetic algorithm (GA) for optimization. The sample fitting variance is 2.42 dB, reducing computation time from 12 min to under 1 millisecond, with the entire optimization completed in less than 100 s. The optimized IPD structure is 0.7 × 0.9 × 0.014 λ03 in size and achieves over 35 dB isolation between the transmitter and receiver. Compared to the IPD model calculated by empirical formulas, the optimized device lowers the average noise figure by 15.2 dB and increases maximum gain by 4.19 dB.

2D materials, particularly transition metal dichalcogenides (TMDCs), have shown great potential for microelectronics and optoelectronics. However, a major challenge in commercializing these materials is the inability to control their doping at a wafer scale with high spatial fidelity. Interface chemistry is used with the underlying substrate oxide and concomitant exposure to visible light in ambient conditions for photo-dedoping wafer scale MoS 2 . It is hypothesized that the oxide layer traps photoexcited holes, leaving behind long-lived electrons that become available for surface reactions with ambient air at sulfur vacancies (defect sites) resulting in dedoping. Additionally, high fidelity spatial control is showcased over the dedoping process, by laser writing, and fine control achieved over the degree of doping by modulating the illumination time and power density. This localized change in MoS 2 doping density is very stable (at least 7 days) and robust to processing conditions like high temperature and vacuum. The scalability and ease of implementation of this approach can address one of the major issues preventing the "Lab to Fab" transition of 2D materials and facilitate its seamless integration for commercial applications in multi-logic devices, inverters, and other optoelectronic devices., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)

Background/Objectives : The aim was to determine the complication rate and the predictors of complications and survival in high-grade glioma surgically managed at progression with implantation of Carmustine wafers. Methods : A retrospective series of 53 consecutive patients operated on between 2017 and 2022 was built. Results : The median age was 55 ± 10.9 years. The rates of global and infectious complications were 35.8% and 18.9%, respectively. In multivariate analysis, patients with a preoperative neurological deficit were more prone to develop a postoperative complication (HR = 5.35 95% CI 1.49-19.26, p = 0.01). No predictor of infectious complication was identified. In the grade 4 glioma subgroup (n = 44), progression-free and overall survival (calculated starting from the reresection) reached 3.95 months, 95% CI 2.92-5.21 and 11.51 months, 95% CI 9.11-17.18, respectively. Preoperative KPS > 80% (HR = 0.97 95% CI 0.93-0.99, p = 0.04), Gross Total Resection (HR = 0.38 95% CI 0.18-0.80, p = 0.01), and 3-month postoperative KPS > 80% (HR = 0.35 95% CI 0.17-0.72, p = 0.004) were predictors of prolonged overall survival. Conclusions : Surgical resection is a relevant option in high-grade gliomas at progression, especially in patients with a preoperative KPS > 80%, without preoperative neurological deficit, and amenable to complete resection. In patients elected for surgery, Carmustine wafer implantation is associated with a high rate of complications. It is consequently critical to closely monitor the patients for whom this option is chosen.

Two-dimensional semiconductors have shown great potential for the development of advanced intelligent optoelectronic systems. Among them, two-dimensional perovskite oxides with compelling optoelectronic performance have been thriving in high-performance photodetection. However, harsh synthesis and defect chemistry severely limit their overall performance and further large-scale heterogeneous integration. Here, we report the wafer-scale integration of highly oriented nanosheets by introducing a charge-assisted oriented assembly film-formation process and confirm its universality and scalability. The shallow-trap dominance induced by structural optimization endows the device with a distinguished performance balance, including high photosensitivity close to that of single nanosheet units and fast response speed. An integrated ultra-flexible 256-pixel device demonstrates the versatility of material-to-substrate integration and conformal imaging functionality. Moreover, the device achieves efficient recognition of multidirectional motion trajectories with an accuracy of over 99.8%. Our work provides prescient insights into the large-area fabrication and utilization of 2D perovskite oxides in advanced optoelectronics., (© 2024. The Author(s).)

There is an increasing demand for p-type semiconductors with scalable growth, excellent device performance, and back-end-of-line (BEOL) compatibility. Recently, tellurium (Te) has emerged as a promising candidate due to its appealing electrical properties and potential low-temperature production. So far, nearly all of the scalable production and integration of Te with complementary metal oxide semiconductor (CMOS) technology have been based on physical vapor deposition. Here we demonstrate wafer-scale atomic layer-deposited (ALD) TeO x /Te heterostructure thin-film transistors with high uniformity and integration compatibility. The wafer-scale uniformity of the film is evidenced by spatial Raman mappings and statistical electrical analysis. Furthermore, surface accumulation-induced good ohmic contact has been observed and explained by the unique band alignment of the charge neutrality level inside the Te valence band. These results demonstrate ALD TeO x /Te as a promising p-type semiconductor for monolithic three-dimensional integration in BEOL CMOS applications incorporated with well-established n-type ALD oxide semiconductors.

Progress in superconducting device and detector technologies over the past decade has realized practical applications in quantum computers, detectors for far-infrared telescopes, and optical communications. Superconducting thin-film materials, however, have remained largely unchanged, with aluminum still being the material of choice for superconducting qubits and niobium compounds for high-frequency/high kinetic inductance devices. Magnesium diboride (MgB 2 ), known for its highest transition temperature ( T = 39 K) among metallic superconductors, is a viable material for elevated temperature and higher frequency superconducting devices moving toward THz frequencies. However, difficulty in synthesizing wafer-scale thin films has prevented implementation of MgB c = 39 K) among metallic superconductors, is a viable material for elevated temperature and higher frequency superconducting devices moving toward THz frequencies. However, difficulty in synthesizing wafer-scale thin films has prevented implementation of MgB 2 devices into the application base of superconducting electronics. Here, we report ultrasmooth (<0.5 nm root-mean-square roughness) and uniform MgB 2 thin (<100 nm) films over 100 mm in diameter and present prototype devices fabricated with these films demonstrating key superconducting properties including an internal quality factor over 10 4 at 4.5 K and high tunable kinetic inductance in the order of tens of pH/sq in a 40 nm thick film. This advancement will enable development of elevated temperature, high-frequency superconducting quantum circuits, and devices.

As an important trace molecular detection technique, surface-enhanced Raman scattering (SERS) has been extensively investigated, while the realization of simple, low-cost, and controllable fabrication of wafer-scale, flexible SERS-active substrates remains challenging. Here, we report a facile, low-cost strategy for fabricating wafer-scale SERS substrates based on Ag-TiO 2 nanoparticle-film hybrids by combining dip-coating and UV light array photo-deposition. The results show that a centimeter-scale Ag nanoparticle (AgNP) film (~20 cm × 20 cm) could be uniformly photo-deposited on both non-flexible and flexible TiO 2 substrates, with a relative standard deviation in particle size of only 5.63%. The large-scale AgNP/TiO 2 hybrids working as SERS substrates show high sensitivity and good uniformity at both the micron and wafer levels, as evidenced by scanning electron microscopy and Raman measurements. In situ bending and tensile experiments demonstrate that the as-prepared flexible AgNP/TiO 2 SERS substrate is mechanically robust, exhibiting stable SERS activity even in a large bending state as well as after more than 200 tensile cycles. Moreover, the flexible AgNP/TiO 2 SERS substrates show excellent performance in detecting sub-micrometer-sized plastics (≤1 μm) and low-concentration organic pollutants on complex surfaces. Overall, this study provides a simple path toward wafer-scale, flexible SERS substrate fabrication, which is a big step for practical applications of the SERS technique.

Polycrystalline lead halide perovskite finds promising use in fabricating X-ray detectors with a large lateral size, adjustable thickness, and diverse synthesis processes. However, a large dark current hinders its development for weak signal detection. Herein, we propose a multistep pressing strategy for manufacturing a CsPbBr 3 /CsPbCl 3 heterojunction wafer for a reduced dark current X-ray detector, and the device keeps a high sensitivity value after the insertion of a barrier by heterojunction; thus, the trade-off between sensitivity and dark current can be broken. The X-ray detector with a metal-semiconductor-metal structure yields a sensitivity of 6.32 × 10 4 μC Gy air -1 cm -2 at a bias of 12 V, a 1/ f noise of 1.02 × 10 -13 A/Hz -1/2 . These performance parameters are considerably better than those of a similar X-ray detector based on the single-structure wafer. The improved device performance of the heterostructure X-ray detector is ascribed to the suppressed carrier recombination, enhanced carrier transportation of the heterojunction, and strong X-ray attenuation of the CsPbCl -1 layer. The pixel array device is further used in imaging applications. Hence, this study provides an efficient strategy for fabricating heterostructure polycrystalline lead halide perovskite wafers for use in high-performance wafer-based X-ray detectors.3 layer. The pixel array device is further used in imaging applications. Hence, this study provides an efficient strategy for fabricating heterostructure polycrystalline lead halide perovskite wafers for use in high-performance wafer-based X-ray detectors.

Purpose: It remains unclear whether combining carmustine wafer (CW) implantation with the standard treatment for adult-type diffuse gliomas is safe and has a prognostic impact. This study aimed to investigate the prognostic value and safety of CW implantation., Methods: Adult patients with IDH-wild-type and -mutant gliomas, grades 3-4 treated with surgical resection, radiotherapy, and temozolomide chemotherapy between 2013 and 2023 were surveyed. CWs were implanted except in cases of intraoperative wide ventricle opening or marked preoperative brain swelling. For survival analyses, a case-matched dataset based on propensity score matching (PSM), including multiple factors (patient background, diagnosis, and extent of resection) was generated. Progression-free survival (PFS), overall survival (OS), and frequency of complications of CW implantation (brain edema, infection, and cerebrospinal fluid leakage) were compared between the CW and non-use groups., Results: In total, 127 patients (75 in the CW use group and 52 in the non-use group) were enrolled. Regardless of stratification, no significant differences in PFS and OS were observed between the CW use and non-use groups. The frequency of postoperative brain edema was significantly higher in the CW use group than in the non-use group. An adjusted dataset containing 41 patients in the CW use and nonuse groups was generated. Even after PSM, CW implantation had no prognostic effect., Conclusions: CW implantation with standard treatment demonstrated little beneficial effect for the present strategy of CW use., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Two-dimensional (2D) palladium diselenide (PdSe 2 ) layers are projected to exhibit a number of intriguing electrical properties such as semiconducting-to-metallic transitions. Precisely modulating their morphology and chemistry is essential for realizing such opportunities, which is particularly demanded on a large dimension under flexible processing conditions toward broadening their practical device applicability. Herein, we explore a wafer-scale growth of 2D PdSe 2 layers and introduce semiconducting-to-metallic transitions into them at as low as 330 °C, a temperature compatible with a range of polymeric substrates as well as the back-end-of-line (BEOL) processes. Two independent physical and chemical approaches of thickness modulation and anion exchange are demonstrated to induce the low-temperature-driven electrical transitions. Wafer-scale 2D PdSe 2 layers grown from a scalable selenization of thin (∼2 nm) Pd exhibit p -type semiconducting characteristics, which completely vanish with increasing thickness. Furthermore, a postgrowth reaction involving an exchange of selenium (Se)-to-tellurium (Te) ions chemically introduces the semiconducting-to-metallic transitions through the conversion of PdSe 2 -to-palladium ditelluride (PdTe 2 ). A significant reduction of the bandgap energy from 0.7 to 0 V is observed to be associated with the transitions, while the converted 2D layers remain to be highly metallic irrespective of thickness variations. These controlled transition characteristics are employed to fabricate "all-2D" flexible devices employing semiconducting 2D layer channels and metallic 2D layer electrodes on a wafer-scale.

Single-oxidant slurries are prevalently utilized in chemical and mechanical polishing (CMP) of 4H-SiC crystal. Nevertheless, it is a challenge to achieve a high material removal rate (MRR) and surface quality using single oxidant slurries to meet the needs of global planarization and damage-free nanoscale surface processing of SiC wafers. To solve this challenge, a novel method is proposed for SiC CMP processing using the double oxidant slurry. This slurry mainly consists of alumina (Al 2 O 3 ) abrasive particles, potassium permanganate (KMnO 4 ), potassium persulfate (K 2 S 2 O 8 ), and deionized water. Post CMP, MRR is 1045 nm/h calculated by scratch method, and surface roughness Sa is 0.33 nm measured by 3D optical surface morphometer, with the measurement area of 868 μm × 868 μm. Both the MRR and Sa are far better than those under the single oxidant slurry condition. CMP mechanism with double-oxidant slurry conditions is elucidated by energy dispersive spectrometer and X-ray photoelectron spectrometer. Initially, the Si-C bond on the SiC wafer surface was oxidized by KMnO 4 , then MnO 2 as the reduction product of KMnO 4 can also catalyze the S 2 O 8 to further oxidize SiC wafer surface, and eventually the oxidation layers were removed by mechanical action of nano-Al 2- to further oxidize SiC wafer surface, and eventually the oxidation layers were removed by mechanical action of nano-Al 2 O 3 abrasive particles during CMP processing. These findings offer a pioneering approach and novel perspectives to achieve a higher MRR of 4H-SiC CMP, with potential implications for the application in high-performance SiC devices.

Diamond-Like Carbon (DLC), a thin-film material, is emerging as a promising alternative for durable surfaces due to its eco-friendly application process. This study evaluated the use of thin-film DLC on the wafer surface of gravure cylinders for roll-to-roll printing of fine-line electrodes and microtext patterns, specifically for applications in flexible electronics and graphics security. Results suggested that using thin film DLC on the wafer surface allows reliable reproduction of isometric grids and line structures with widths of 15, 20, and 30 µm, as well as solid electrodes. The uniform conformity of thin-film DLC on the wafer surface, featuring an engraved micron-size cell structure, demonstrates superior ink transfer onto flexible PET (polyethylene terephthalate) substrates. This results in increased electrode line width and reduced electrical resistance compared to chrome. Statistical analysis confirmed the reliability and repeatability of the findings. Visual analysis of lines and microtext also demonstrated the reliable print-reproducing capabilities of DLC-coated surfaces. Overall, these results suggest that thin-film DLC is a promising alternative for use as a protective layer on gravure wafer surfaces. It has the potential to produce high-quality, high-volume electronics, such as sensors, antennas, and batteries, for applications in the Internet of Things (IoT) and other sustainable technologies., (© 2024 Wiley‐VCH GmbH.)

As the trajectory toward the graphene era continues, there is a compelling need to harness 2D technology further for the transformation of three-dimensional (3D) materials production and applications. Here, we resolve this challenge for one of the most widely utilized 3D materials in modern electronics─gold─using graphene-inspired fabrication technology that allows us to develop a multistep production method of ultrathin gold films. Such films demonstrate continuous morphology, low sheet resistance (10 Ω/sq), and high transparency (80%), offering opportunities in a variety of technological and scientific sectors. To this end, we demonstrate smart contact lenses and thermal camouflage based on ultrathin gold. Technologically, the record-breaking characteristics of ultrathin gold films open new horizons for flexible and transparent electrodes for photonics and optoelectronics. Most importantly, the demonstration of transferable wafer-scale ultrathin gold changes the paradigm of the field of 2D crystals and dramatically expands the range of available quasi-2D materials.

Two-dimensional MoS 2 semiconductors have emerged as a promising solution for extending Moore's law. Nevertheless, their wafer-scale growth from lab to fab is still in infancy stages within the semiconductor industry. The distribution, concentration, and reactivity of both sulfur and molybdenum precursors exert a substantial influence on the uniformity of MoS 2 wafers, including on parameters such as the grain size, thickness, and vacancy density. While considerable emphasis has been directed towards sulfur precursors-such as those derived from ZnS, which facilitate MoS 2 growth-the role of molybdenum precursors and their associated growth mechanisms remain inadequately understood. In this study, we investigated the effects of covalent and ionic molybdenum precursors, grounded in the principles of chemical vapor deposition, with the aim of identifying a universal synthesis pathway for wafer production. Our findings indicate that the reaction kinetics of Na 2 MoO 4 , a representative ionic precursor, are particularly advantageous for controlling wafer growth defects and enhancing surface homogeneity in comparison to those of MoO 3 , a conventional covalent precursor. Evaporated [MoO 4 ] 2- ions, characterized by their smaller cluster size, exhibited high reactivity, facilitating uniform control over MoS 2 wafer characteristics. Furthermore, we demonstrate that a 2-inch monolayer MoS 2 film could be synthesized within a growth timeframe of 3-5 minutes using ionic precursors, achieving a mobility of 12 cm 2 V -1 s -1 and a maximum I on / I off ratio of 9.87 × 10 9 . This study elucidates the growth mechanisms of MoS 2 wafers and contributes to the advancement of MoS 2 -based electronic systems.

The helicity-dependent photocurrent (HDPC) of Fe 4 GeTe 2 (3, 5, 8, 10 nm)/Bi 2 Te 3 (8 nm) heterostructures grown on sapphire substrates was systematically investigated. It is revealed that the HDPC is induced by the interface coupling between the Fe 4 GeTe 2 and Bi 2 Te 3 films, and it is dominated by the circular photogalvanic effect (CPGE) rather than by the circular photodrag effect (circular photon drag effect). As the tensile strain increases, the CPGE current decreases, which can be attributed to the decrease of the interface-induced spin-orbit coupling with increasing tensile strain. In addition, it is demonstrated that by applying appropriate tensile strain, the 5 nm Fe 4 GeTe 2 /Bi 2 Te 3 sample can be used to detect the circular polarization state of a light. Finally, Fe 4 GeTe 2 (5, 8, and 10 nm)/Bi 2 Te 3 (8 nm) heterostructures show a T C larger than 390 K. The dependence of the CPGE on the film thickness of Fe 4 GeTe 2 is different from that of Curie temperature, indicating that the enhanced exchange interaction induced by the interface coupling may be the dominant mechanism for the high- T C ferromagnetism. The large interface-induced CPGE in the Fe 4 GeTe 2 /Bi 2 Te 3 suggests that Fe 4 GeTe 2 /Bi 2 Te 3 heterostructures may provide a good platform for designing novel opto-spintronic devices.

Halide perovskites (HPs) have demonstrated excellent direct X-ray detection performance. Lead-free perovskite polycrystalline wafers have outstanding advantages in large-area X-ray imaging applications due to their area-scalability, thickness-controllability, large bulk resistivity, and ease of integration with large-area thin film transistor arrays. However, currently lead-free perovskite polycrystalline wafers possess low sensitivity, typically less than 1000 µC Gy -1 cm -2 , which severely limits their X-ray detection applications. Here, high-quality and large scale polycrystalline wafers of AG 3 Bi 2 I 9 (AG: aminoguanidinium) with short intercluster distances are successfully prepared using a hot-pressing method. The wafers possess high mobility-lifetime product of 5.66 × 10 -3 cm 2 V -1 and therefore achieve high X-ray sensitivity of 2675 µC Gy -1 cm -2 , which can be comparable to those of the high-quality single crystal counterpart reported by the previous research (7.94 × 10 -3 cm 2 V -1 and 5791 µC Gy -1 cm -2 ), and represent the best results of the currently lead-free HP polycrystalline wafers. Besides, the wafers exhibit the X-ray detection limit as low as 11.8 nGy s -1 , excellent long-term working stability, and high spatial resolution of 5.9 lp mm -1 in imaging. The findings demonstrate that AG 3 Bi 2 I 9 polycrystalline wafers are feasible for high-performance X-ray detection and imaging system., (© 2024 Wiley‐VCH GmbH.)

Synthesizing high-crystalline covalent organic framework films is highly desired to advance their applications in two-dimensional optoelectronics, but it remains a great challenge. Here, we report a diffusion-limited synthesis strategy for wafer-scale uniform covalent organic framework films, in which pre-deposited 4,4',4″,4‴-(1,3,6,8-Tetrakis(4-aminophenyl) pyrene is encapsulated on substrate surface with a layer of covalent organic framework prepolymer. The polymer not only prevents the dissolution of precursor, but limits the reaction with terephthalaldehyde dissolved in solution, thereby regulating the polymerization process. The size depends on growth substrates, and 4-inch films have been synthesized on silicon chips. Their structure, thickness, patterning and crystallization degree can be controlled by adjusting building blocks and polymerization chemistries, and molybdenum disulfide have been used as substrates to construct vertical heterostructure. The measurements reveal that using covalent organic framework as a photosensitive layer, the heterojunction displays enhanced photoelectric performance, which can be used to simulate the adaptative function of visual system., Competing Interests: Competing interests: The authors declare no conflicting interest., (© 2024. The Author(s).)

High purity silicon is considered as the test mass material for future cryogenic gravitational-wave detectors, in particular Einstein Telescope-low frequency and LIGO Voyager [(LIGO) Laser Interferometer Gravitational-Wave Observatory]. To reduce the thermal noise of the test masses, it is necessary to study the sources of corresponding losses. Mechanical resonators with frequencies 300 Hz-6 kHz are successfully used for studying, for example, losses in optical coatings of the test mass. However, the frequency range of the interferometric gravitational-wave detectors starts at 10 Hz, and the investigation of different dissipation mechanisms for the test masses in the low-frequency region is relevant. We developed a design of a four-spiral mechanical resonator for studying dissipation and noise in the low frequency range. The resonator was fabricated of a 3-in. silicon wafer using an anisotropic wet etching technique. It consists of four spiral cantilevers on a common base, linked together with additional coupling beams for increasing the frequency difference between the resonator normal modes corresponding to the fundamental flexural off-plane mode of a single spiral cantilever. The measured Q-factor of the 62 Hz out-of-phase mode of the four-spiral silicon resonator at room temperature is limited mainly by the thermoelastic loss. At 123 K, the measured Q = (1.5 ± 0.3) × 107. The main contribution to the total loss comes from clamping and surface losses., (© 2024 Author(s). Published under an exclusive license by AIP Publishing.)

Tribological printing is emerging as a promising technique for micro/nano manufacturing. A significant challenge is enhancing efficiency and minimizing the need for thousands of sliding cycles to create nano- or microstructures (2018 ACS Appl. Mater. Inter. 10  335-47, 2019 Nanotechnology 30  302 ). This study presents a rapid approach for forming Cu microwires on Si wafers through a friction method during the evaporation of an ethanol-based lubricant containing Cu nanoparticles. The preparation time is influenced by the volume of the lubricant added, with optimal conditions reducing the time to 300 s (600 sliding cycles) for producing Cu microwires with a thickness of 200 nm. Key aspects include the lubricating effect of ethanol on the friction pairs and the role of ethanol evaporation in the growth of Cu microwires. Successful formation requires a careful balance between microwire thickening and wear removal. The resulting Cu microwires demonstrate mechanical and electrical properties that make them suitable as micro conductors. This work provides a novel approach for fabricating conductive microstructures on Si surfaces and other curved surfaces, offering potential applications in microelectronics and sensor technologies., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

van der Waals (vdW) heterostructures constructed by low-dimensional (0D, 1D, and 2D) materials are emerging as one of the most appealing systems in next-generation flexible photodetection. Currently, hand-stacked vdW-type photodetectors are not compatible with large-area-array fabrication and show unimpressive performance in self-powered mode. Herein, vertical 1D GaN nanorods arrays (NRAs)/2D MoS 2 /PEDOT:PSS in wafer scale have been proposed for self-powered flexible photodetectors arrays firstly. The as-integrated device without external bias under weak UV illumination exhibits a competitive responsivity of 1.47 A W -1 and a high detectivity of 1.2 × 10 11 Jones, as well as a fast response speed of 54/71 µs, thanks to the strong light absorption of GaN NRAs and the efficient photogenerated carrier separation in type-II heterojunction. Notably, the strain-tunable photodetection performances of device have been demonstrated. Impressively, the device at - 0.78% strain and zero bias reveals a significantly enhanced photoresponse with a responsivity of 2.47 A W -1 , a detectivity of 2.6 × 10 11 Jones, and response times of 40/45 µs, which are superior to the state-of-the-art self-powered flexible photodetectors. This work presents a valuable avenue to prepare tunable vdWs heterostructures for self-powered flexible photodetection, which performs well in flexible sensors., (© 2024. The Author(s).)

Whispering Gallery Mode (WGM) optomechanical resonators are a promising technology for the simultaneous control and measurement of optical and mechanical degrees of freedom at the nanoscale. They offer potential for use across a wide range of applications such as sensors and quantum transducers. Double-disk WGM resonators, which host strongly interacting mechanical and optical modes co-localized around their circumference, are particularly attractive due to their high optomechanical coupling. Large-scale integrated fabrication of silicon double-disk WGM resonators has not previously been demonstrated. In this work, we present a process for the fabrication of double-layer silicon-on-insulator wafers, which we then use to fabricate functional optomechanical double silicon disk resonators with on-chip optical coupling. The integrated devices present experimentally observed optical quality factors of the order of 10 5 and a single-photon optomechanical coupling of approximately 15 kHz.

Near-infrared laser-pumped optical rectification (OR) using quasi-phase matching (QPM) in lithium niobate (LN) is widely employed to generate multi-cycle terahertz (THz) pulses, which, however, suffer from low efficiency. Here, we demonstrate that mid-infrared pumping is an effective approach to increase the efficiency of multi-cycle THz generation. By using a 2.3-µm laser to pump a QPM macro-crystal composed of ten x-cut lithium niobate wafers, with their ferroelectric Z axis alternately rotated by π, a laser-to-THz conversion efficiency up to ∼0.4% has been achieved at room temperature, more than twice the efficiencies attained with near-infrared pumping. Electro-optic sampling reveals the generation of five-cycle THz pulses at 0.15 THz for 350-µm-thick wafers and 0.22 THz for 250-µm-thick wafers. Such mid-infrared laser-pumped OR in QPM wafer stacks provides an efficient, controllable, and scalable method for generating intense multi-cycle THz pulses suitable for diverse narrow-bandwidth applications.

Free-standing gallium nitride has been prepared using various methods; however, the removal of the original substrate is still challenging with low success rates. In this work, 2-inch free-standing GaN films are obtained by direct growth on a fluoro phlogopite mica by hydride vapor-phase epitaxy. Depending on the van der Waals (vdW) interaction between GaN and mica, the effect of the significant lattice mismatch is effectively reduced; thus, enabling the production of a high-quality wafer-scale GaN film on mica. The vdW-induced cracks at GaN-mica interface are found to be initiated near the interface so that GaN can easily separate from mica during rapid cooling. Owing to the hydrophilic nature of mica, the residual GaN on the mica can be lifted off by following deionized water treatment, and the mica substrate can be repeatedly used to grow free-standing GaN films. The self-separated GaN films grown on both pristine and used mica substrates are single crystallinity and strain-free. Additionally, a fully functional ultraviolet light-emitting diode is demonstrated to show that the self-separated GaN films are of device quality. The proposed approach achieves epitaxial growth of wafer-scale single-crystalline GaN on 2D materials and provides a new substrate option in the technology of III-V materials., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

The development of catalysts that are optically transparent, electrically charge-transferable, and capable of protecting underlying photoactive semiconductors is crucial for efficient photoelectrochemical (PEC) hydrogen production. However, meeting all these requirements simultaneously poses significant challenges. In this study, the fabrication of a wafer-scale transparent bilayer MoS 2 /WS 2 catalyst is presented with a staggered heterojunction, optimized for photon absorption, extraction of photogenerated charge carriers, and surface passivation of p-Si photocathode. The MoS 2 and WS 2 monolayers are grown via metal-organic chemical vapor deposition, followed by sequential transfer and stacking onto the p-Si photocathode. The resulting type-II heterojunction film establishes a strong built-in electric field for rapid charge carrier transport and effectively protects the Si surface from oxidation and corrosion. The fabricated MoS 2 /WS 2 /p-Si photocathode demonstrates outstanding PEC performance, achieving a high photocurrent density of -25 mA cm -2 at 0 V versus reversible hydrogen electrode, along with enhanced stability compared to monolayer MoS 2 /p-Si. This work provides promising strategies for developing optically transparent, electrically active, and protective catalysts for practical PEC energy conversion systems., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

A ground-breaking roadmap of III-nitride solid-state deep-ultraviolet light emitters is demonstrated to realize the wafer-scale fabrication of devices in vertical injection configuration, from 2 to 4 inches. The epitaxial device structure is stacked on a GaN template instead of conventionally adopted AlN, where the primary concern of the tensile strain for Al-rich AlGaN on GaN is addressed via an innovative decoupling strategy, making the device structure decoupled from the underlying GaN template. Moreover, the strategy provides a protection cushion against the stress mutation during the removal of substrates. As such, large-sized wafers can be obtained without surface cracks, even after the removal of the sapphire substrates by laser lift-off. Wafer-scale fabrication of 280 nm vertical injection deep-ultraviolet light-emitting diodes is eventually demonstrated, where a light output power of 65.2 mW is achieved at a current of 200 mA, largely thanks to the significant improvement of light extraction. This work will definitely speed up the application of III-nitride solid-state deep-ultraviolet light emitters featuring high performance and scalability., (© 2024. The Author(s).)

Owing to high pixel density and brightness, gallium nitride (GaN) based micro-light-emitting diodes (Micro-LEDs) are considered revolutionary display technology and have important application prospects in the fields of micro-display and virtual display. However, Micro-LEDs with pixel sizes smaller than 10 μm still encounter technical challenges such as sidewall damage and limited light extraction efficiency, resulting in reduced luminous efficiency and severe brightness non-uniformity. Here, we reported high-brightness green Micro-displays with a 5 μm pixel utilizing high-quality GaN-on-Si epilayers. Four-inch wafer-scale uniform green GaN epilayer is first grown on silicon substrate, which possesses a low dislocation density of 5.25 × 10 8  cm - , small wafer bowing of 16.7 μm, and high wavelength uniformity (standard deviation STDEV < 1 nm), scalable to 6-inch sizes. Based on the high-quality GaN epilayers, green Micro-LEDs with 5 μm pixel sizes are designed with vertical non-alignment bonding technology. An atomic sidewall passivation method combined with wet treatment successfully addressed the Micro-LED sidewall damages and steadily produced nano-scale surface textures on the pixel top, which unlocked the internal quantum efficiency of the high-quality green GaN-on-Si epi-wafer. Ultra-high brightness exceeding 10 2 , small wafer bowing of 16.7 μm, and high wavelength uniformity (standard deviation STDEV < 1 nm), scalable to 6-inch sizes. Based on the high-quality GaN epilayers, green Micro-LEDs with 5 μm pixel sizes are designed with vertical non-alignment bonding technology. An atomic sidewall passivation method combined with wet treatment successfully addressed the Micro-LED sidewall damages and steadily produced nano-scale surface textures on the pixel top, which unlocked the internal quantum efficiency of the high-quality green GaN-on-Si epi-wafer. Ultra-high brightness exceeding 10 7  cd/m 2 (nits) is thus achieved in the green Micro-LEDs, marking the highest reported results. Furthermore, integration of Micro-LEDs with Si-based CMOS circuits enables the realization of green Micro-LED displays with resolution up to 1080 × 780, realizing high-definition playback of movies and images. This work lays the foundation for the mass production of high-brightness Micro-LED displays on large-size GaN-on-Si epi-wafers., (© 2024. The Author(s).)

Monocrystalline chalcogenide thin films in freestanding forms are very much needed in advanced electronics such as flexible phase change memories (PCMs). However, they are difficult to manufacture in a scalable manner due to their growth and delamination challenges. Herein, we report a viable strategy for a wafer-scale epitaxial growth of monocrystalline germanium telluride (GeTe) membranes and their deterministic integrations onto flexible substrates. GeTe films are epitaxially grown on Ge wafers via a tellurization reaction accompanying a formation of confined dislocations along GeTe/Ge interfaces. The as-grown films are subsequently delaminated off the wafers, preserving their wafer-scale structural integrity, enabled by a strain-engineered spalling method that leverages the stress-concentrated dislocations. The versatility of this wafer epitaxy and delamination approach is further expanded to manufacture other chalcogenide membranes, such as germanium selenide (GeSe). These materials exhibit phase change-driven electrical switching characteristics even in freestanding forms, opening up unprecedented opportunities for flexible PCM technologies.

Quasi-3D plasmonic nanostructures are in high demand for their ability to manipulate and enhance light-matter interactions at subwavelength scales, making them promising building blocks for diverse nanophotonic devices. Despite their potential, the integration of these nanostructures with optical sensors and imaging systems on a large scale poses challenges. Here, a robust technique for the rapid, scalable, and seamless replication of quasi-3D plasmonic nanostructures is presented straight from their production wafers using a microbubble process. This approach not only simplifies the integration of quasi-3D plasmonic nanostructures into a wide range of standard and custom optical imaging devices and sensors but also significantly enhances their imaging and sensing performance beyond the limits of conventional methods. This study encompasses experimental, computational, and theoretical investigations, and it fully elucidates the operational mechanism. Additionally, it explores a versatile set of options for outfitting nanophotonic devices with custom-designed plasmonic nanostructures, thereby fulfilling specific operational criteria., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Wafer-scale transfer processes of 2D materials significantly expand their application space in scalable microelectronic devices with excellent and tunable properties through van der Waals (vdW) stacking. Unlike many 2D materials, wafer-scale transfer of MXene films for vdW contact engineering has not yet been reported. With their rich surface chemistry and tunable properties, the transfer of MXenes can enable enormous possibilities in electronic devices using interface engineering. Taking advantage of the MXene hydrophilic surface, a straightforward, green, and fast process for the transfer of MXene films at the wafer scale (4-inch) is developed. Uniform vdW stacking of several types of large-area heterojunctions including MXene/MXene (Ti 3 C 2 T x , Nb 2 CT x, and V 2 CT x ), MXene/MoS 2 , and MXene/Au is further demonstrated. Multilayer support is applied to minimize damage or deformation in the transfer process of patterned Ti 3 C 2 T x film. It allows us to fabricate thin film transistors and manipulate the MXene/MoS 2 interface through the intercalation of various 2D liquids. Particularly noteworthy is the significant enhancement of the interfacial carrier transfer efficiency by ≈2 orders of magnitude using hydrogen iodide (HI) intercalation. This finding indicates a wide range of possibilities for interface engineering by transferring MXene films and employing liquid-assisted interfacial intercalation., (© 2024 Wiley‐VCH GmbH.)

As integrated circuits continue to scale toward the atomic limit, bottom-up processes, such as epitaxial growth, have come to feature prominently in their fabrication. At the same time, chemistry has developed highly tunable molecular semiconductors that can perform the functions of ultimately scaled circuit components. Hybrid techniques that integrate programmable structures comprising molecular components into devices however are sorely lacking. Here we demonstrate a wafer-scale process that directs the localization of a conductive polymer, M w = 20 kg mol -1 polyaniline, from dilute solutions into 50 nm vertical nanogap device architectures using electric-field-driven self-assembly. The resulting metal-polymer-metal junctions were characterized by electron microscopy, Raman spectroscopy and transport measurements demonstrating that our technique is highly selective, assembling conductive polymers only in electrically activated nanogaps. Our results represent a step toward scalable hybrid nanoelectronics that seamlessly integrate established lithographic top-down fabrication with bottom-up synthesized molecular functional circuit components.

The out-of-control action plan (OCAP) is crucial in the wafer probing process of semiconductor manufacturing as it systematically addresses and corrects deviations, ensuring the high quality and reliability of semiconductor devices. However, the traditional OCAP involves many redundant and complicated processes after failures occur on production lines, which can delay production and escalate costs. To overcome the traditional OCAP's limitations, this paper proposes a novel OCAP aimed at enhancing the wafer probing process in semiconductor manufacturing. The proposed OCAP integrates proactive measures such as preventive maintenance and advanced monitoring technologies, which are tested and verified through a comprehensive experimental setup. Implementing the novel OCAP in a case company's production line reduced machine downtime by over 24 h per week and increased wafer production by about 23 wafers per week. Additionally, probe test yield improved by an average of 1.1%, demonstrating the effectiveness of the proposed method. This paper not only explores the implementation of the novel OCAP but also compares it with the traditional OCAP, highlighting significant improvements in efficiency and production output. The results underscore the potential of advanced OCAP to enhance manufacturing processes by reducing dependency on human judgment, thus lowering the likelihood of errors and improving overall equipment effectiveness (OEE).

The tunable properties of 2D transition-metal dichalcogenide (TMDs) materials are extensively investigated for high-performance and wavelength-tunable optoelectronic applications. However, the precise modification of large-scale systems for practical optoelectronic applications remains a challenge. In this study, a wafer-scale atomic assembly process to produce 2D multinary (binary, ternary, and quaternary) TMDs for broadband photodetection is demonstrated. The large-area growth of homogeneous MoS 2 , Ni 0.06 Mo 0.26 S 0.68 , and Ni 0.1 Mo 0.9 S 1.79 Se 0.21 is carried out using a succinct coating of the single-source precursor and subsequent thermal decomposition combined with thermal evaporation of the chalcogen powder. The optoelectrical properties of the multinary TMDs are dependent on the combination of heteroatoms. The maximum photoresponsivity of the MoS 2 -, Ni 0.06 Mo 0.26 S 0.68 -, and Ni 0.1 Mo 0.9 S 1.79 Se 0.21 -based photodetectors is 3.51 × 10 -4 , 1.48, and 0.9 A W -1 for 532 nm and 0.063, 0.42, and 1.4 A W -1 for 1064 nm, respectively. The devices exhibited excellent photoelectrical properties, which is highly beneficial for visible and near-infrared (NIR) photodetection., (© 2024 The Authors. Small published by Wiley‐VCH GmbH.)

This paper introduces a cost-effective, high-performance approach to achieving wafer level vacuum packaging (WLVP) for MEMS-based uncooled infrared sensors. Reliable and hermetic packages for MEMS devices are achieved using a cap wafer that is formed using two silicon wafers, where one wafer has precise grating/moth-eye structures on both sides of a double-sided polished wafer for improved transmission of over 80% in the long-wave infrared (LWIR) wavelength region without the need for an AR coating, while the other wafer is used to form a cavity. The two wafers are bonded using Au-In transient liquid phase (TLP) bonding at low temperature to form the cap wafer, which is then bondelectrical and Electronics d to the sensor wafer using glass frit bonding at high temperature to activate the getter inside the cavity region. The bond quality is assessed using three methods, including He-leak tests, cap deflection, and Pirani vacuum gauges. Hermeticity is confirmed through He-leak tests according to MIL-STD 883, yielding values as low as 0.1 × 10 -9 atm·cc/s. The average shear strength is measured as 23.38 MPa. The package pressure varies from 133-533 Pa without the getter usage to as low as 0.13 Pa with the getter usage.

Stretchable organic phototransistor arrays have potential applications in artificial visual systems due to their capacity to perceive ultraweak light across a broad spectrum. Ensuring uniform mechanical and electrical performance of individual devices within these arrays requires semiconductor films with large-area scale, well-defined orientation, and stretchability. However, the progress of stretchable phototransistors is primarily impeded by their limited electrical properties and photodetection capabilities. Herein, wafer-scale and well-oriented semiconductor films were successfully prepared using a solution shearing process. The electrical properties and photodetection capabilities were optimized by improving the polymer chain alignment. Furthermore, a stretchable 10 × 10 transistor array with high device uniformity was fabricated, demonstrating excellent mechanical robustness and photosensitive imaging ability. These arrays based on highly stretchable and well-oriented wafer-scale semiconductor films have great application potential in the field of electronic eye and artificial visual systems.

Background : Ulnar impaction syndrome (UIS) is a common degenerative wrist condition which results from positive ulnar variance, leading to an overload on the ulnar carpus. Ulnar shortening osteotomy (USO) and the arthroscopic wafer procedure (AWP) are established therapies for UIS if conservative management fails. This study assessed an algorithm-guided treatment of UIS over a period of 10 years. Methods: This prospective observational study compared the outcome of 54 patients who underwent either USO or AWP for UIS based on a predefined treatment algorithm. The mean follow-up period was 10 years. Primary outcome parameters were the visual analogue scale (VAS) for pain and the Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH), whereas secondary outcome parameters were grip and pinch strength and range of motion. Results: The median preoperative ulnar variance was 2.6 mm in the USO group and 2.0 mm in the AWP group. The postoperative average ulnar variance was 0 mm in both groups. The preoperative pain at rest was 3.4 in the USO group and 2.3 in the AWP group. One year after surgery, there was a significant reduction to VAS 0.7 and 0.2, respectively. These results persisted to the 10-year follow-up (VAS 0.9 and 0.2). The pain in motion also decreased significantly in the first year (from 6.8 and 6.7 to 2.2 and 2.1), as well as after 10 years (2.4 and 1.0). The preoperative DASH score averaged 31.3 in the USO group and 35.8 in the AWP group. At the 10-year follow-up, the DASH of both groups decreased significantly to 4.35 in the AWP group compared to 12.7 in the USO group. Conclusions : Our data show that, when using our algorithm, both USO and AWP, two common operative treatment options of UIS, reliably reduce pain and significantly reduce the DASH score over at least a period of ten years. The results after 10 years differ from short-term results in so far as after one year, the USO group showed to some degree similar outcome parameters compared to AWP, whereas at the 10-year follow-up, AWP reached slightly better primary outcome parameters. The algorithm presented, thus, produced excellent short- and long-term outcomes. Our findings and the applied algorithm can assist in decision-making and patient education.

Large-scale, high-quality, and uniform monolayer molybdenum disulfide (MoS 2 ) films are crucial for their applications in next-generation electronics and optoelectronics. Epitaxy is a mainstream technique for achieving high-quality MoS 2 films and is demonstrated at a wafer scale up to 4-in. In this study, the epitaxial growth of 8-in. wafer-scale highly oriented monolayer MoS 2 on sapphire is reported as with excellent spatial homogeneity, using a specially designed vertical chemical vapor deposition (VCVD) system. Field effect transistors (FETs) based on the as-grown 8-in. wafer-scale monolayer MoS 2 film are fabricated and exhibit high performances, with an average mobility and an on/off ratio of 53.5 cm 2 V -1 s -1 and 10 7 , respectively. In addition, batch fabrication of logic devices and 11-stage ring oscillators are also demonstrated, showcasing excellent electrical functions. This work may pave the way of MoS 2 in practical industry-scale applications., (© 2024 The Authors. Advanced Materials published by Wiley‐VCH GmbH.)

The disparity between growth substrates and application-specific substrates can be mediated by reliable graphene transfer, the lack of which currently strongly hinders the graphene applications. Conventionally, the removal of soft polymers, that support the graphene during the transfer, would contaminate graphene surface, produce cracks, and leave unprotected graphene surface sensitive to airborne contaminations. In this work, it is found that polyacrylonitrile (PAN) can function as polymer medium for transferring wafer-size graphene, and encapsulating layer to deliver high-performance graphene devices. Therefore, PAN, that is compatible with device fabrication, does not need to be removed for subsequent applications. The crack-free transfer of 4 in. graphene onto SiO 2 /Si wafers, and the wafer-scale fabrication of graphene-based field-effect transistor arrays with no observed clear doping, uniformly high carrier mobility (≈11 000 cm 2 V -1 s -1 ), and long-term stability at room temperature, are achieved. This work presents new concept for designing the transfer process of 2D materials, in which multifunctional polymer can be retained, and offers a reliable method for fabricating wafer-scale devices of 2D materials with outstanding performance., (© 2024 Wiley‐VCH GmbH.)

Bi 2 S 3 with a 2D van der Waals structure has attracted much attention due to its high conductivity, large absorption coefficient, and environmental friendliness. The preparation of tunable optoelectronic devices can be realized by exploiting and tuning Bi 2 S 3 intrinsic defects. In this work, a simple and rapid method for the preparation of bismuth sulfide thin films and successfully prepare Bi 2 S 3 with sulfur vacancies (S vac ) (LA-Bi 2 S 3 ) and oxygen passivated (S vac ) (AP-Bi 2 S 3 ) was presented. The defect state difference of the two devices leads to exhibit different optoelectronic properties. Under 638 nm and 1310 nm illuminations, the LA-Bi 2 S 3 photodetectors exhibit responsivities of up to 2250 and 3.6 mA/W and detectivities of 1.69 × 10 12 and 2.6 × 10 9 cm·Hz 1/2 W -1 , while the AP-Bi 2 S 3 photodetectors have ultra-fast on/off speeds of 1 ms and 8 ms, and on/off ratio up to 3 × 10 3 . The preparation method of the tunable optoelectronic devices gives a new avenue for defect tuning in metal sulfides and for the preparation and application of optoelectronic devices., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

The relative motion of the reticle stage and wafer stage caused by vibration during the scanning exposure process of the lithography machine is an important factor that affects the imaging quality under limited lithography ability. In this paper, the influence of the vibration of the lithography stage system on the lithography imaging quality is studied. The lithography model including the vibration error of the stage is taken into account in the framework of source and mask optimization (SMO). For the 193-nm immersion lithography machine, combined with different design patterns with a line width of 40 nm and different vibration states of the stage when the lithography machine is exposed, the SMO joint optimization research is carried out, and the robustness of the stage under the limit process after SMO optimization is explored. The research results show that the contrast and relative light intensity change of the limit design figure under the influence of moving standard deviation (MSD) will greatly affect the linewidth at the light intensity threshold and then affect the process window (PW). The SMO including MSD allows the MSD to change in the range of 0-6 nm without changing the PW.

We describe a process for fabricating a wafer-scale array of alkali metal vapor cells with low residual gas pressure. We show that by etching long, thin channels between the cells on the Si wafer surface, the residual gas pressure in the evacuated vapor cell can be reduced to below 0.5 kPa (4 Torr) with a yield above 50%. The low residual gas pressure in these mass-producible alkali vapor cells can enable a new generation of low-cost chip-scale atomic devices such as vapor cell optical clocks, wavelength references, and Rydberg sensors.

Transition metal disulfide compounds (TMDCs) emerges as the promising candidate for new-generation flexible (opto-)electronic device fabrication. However, the harsh growth condition of TMDCs results in the necessity of using hard dielectric substrates, and thus the additional transfer process is essential but still challenging. Here, an efficient strategy for preparation and easy separation-transfer of high-uniform and quality-enhanced MoS 2 via the precursor pre-annealing on the designed graphene inserting layer is demonstrated. Based on the novel strategy, it achieves the intact separation and transfer of a 2-inch MoS 2 array onto the flexible resin. It reveals that the graphene inserting layer not only enhances MoS 2 quality but also decreases interfacial adhesion for easy separation-transfer, which achieves a high yield of ≈99.83%. The theoretical calculations show that the chemical bonding formation at the growth interface has been eliminated by graphene. The separable graphene serves as a photocarrier transportation channel, making a largely enhanced responsivity up to 6.86 mA W -1 , and the photodetector array also qualifies for imaging featured with high contrast. The flexible device exhibits high bending stability, which preserves almost 100% of initial performance after 5000 cycles. The proposed novel TMDCs growth and separation-transfer strategy lightens their significance for advances in curved and wearable (opto-)electronic applications., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)