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Photodetectors have a wide range of applications across various fields. Self-powered photodetectors that do not require external energy have garnered significant attention. The photoelectrochemical type of photodetector is a self-powered device that is both simple to fabricate and offers high performance. However, developing photoelectrochemical photodetectors with superior quality and performance remains a significant challenge. The electrolyte, which is a key component in these detectors, must maintain extensive contact with the semiconductor without degrading its material quality and efficiently catalyze the redox reactions of photogenerated electrons and holes, while also facilitating rapid charge carrier transport. In this study, α -Ga2O3 nanorod arrays were synthesized via a cost-effective hydrothermal method to achieve a self-powered solar-blind photodetector. The impacts of different electrolytes—Na2SO4, NaOH, and Na2CO3—on the photodetector was investigated. Ultimately, a self-powered photodetector with Na2SO4 as the electrolyte demonstrated a stable photoresponse, with the maximum responsivity of 0.2 mA/W at 262 nm with the light intensity of 3.0 mW/cm2, and it exhibited rise and decay times of 0.16 s and 0.10 s, respectively. The α -Ga2O3 nanorod arrays and Na2SO4 electrolyte provided a rapid pathway for the transport of photogenerated carriers and the built-in electric field at the semiconductor–liquid heterojunction interface, which was largely responsible for the effective separation of photogenerated electron–hole pairs that provided the outstanding performance of our photodetector. [ABSTRACT FROM AUTHOR]

All‐inorganic metal halide perovskites are competitive candidate as next‐generation flexible photodetectors (PDs) materials due to the remarkable photoelectric properties, enhanced heat stability, and mechanical flexibility. However, constructing low‐cost flexible perovskites PDs with high photodetection performance, good operation stability and mechanical robustness, and manufacturing corresponding flexible PDs array have been a challenge. Herein, the PbCl2 and Zinc(II) Dibenzyldithiocarbamate (Zn(DBDTC)2) are employed to modify bottom and top interface of CsPbIBr2 perovskite layer, respectively, to passivate surface trap state, enhance hydrophobicity and resist phase segregation, and improve interface contact. Consequently, the self‐powered champion PDs with low‐cost Bi2Te3 electrode reach a responsivity of 0.38 A W−1 and a maximum detectivity of 3.44 × 1013 Jones at 570 nm, and maintain the outstanding long‐term and operational stability without additional encapsulation. Meanwhile, the HTL‐free flexible PDs based on low‐temperature CsPbIBr2 perovskite layer exhibit impressive photodetection performance and mechanical robustness in bending test. More importantly, the flexible PDs array (5 × 5 pixels) and corresponding imaging system are fabricated with uniform and clear imaging results under flatting and bending state. This research is of great significance for the application of stable and high‐performance inorganic perovskites PDs and flexible array imaging systems. [ABSTRACT FROM AUTHOR]

Self-powered full-spectrum photodetectors (PDs) offer numerous advantages, such as broad application fields, high precision, efficiency, and multi-functionality, which represent a highly promising and potentially valuable class of detectors for future development. However, insensitive response to solar-blind ultraviolet (UV) and complex and expensive preparation processes greatly limit their performance and practical application. In this study, a self-powered full-spectrum Bi2Se3/a-Ga2O3/p-Si heterojunction PD with high sensitivity for solar-blind UV band prepared by a simple and low-cost two-step synthesis method is presented. Experiments results reveal that the developed PD has an excellent performance, such as high sensitivity from 200 to 850 nm, and a responsivity of 1.38 mA/W as well as a detectivity of 3.22 × 1010 Jones under 254 nm light at zero bias. Additionally, the unencapsulated device displays exceptional stability and imaging capabilities. It is expected that Bi2Se3/a-Ga2O3/p-Si heterojunction PD with a simple and low-cost synthesis method has great potential for self-powered full-spectrum photodetectors. [ABSTRACT FROM AUTHOR]

Broadband photodetectors with self-driven functions have attracted intensive scientific interest due to their low energy consumption and high optical gain. However, high-performance broadband self-driven photodetectors are still a significant challenge due to the complex fabrication processes, environmental toxicity, high production costs of traditional 3D semiconductor materials and sharply raised contact resistance, severe interfacial recombination of 2D materials and 2D/3D mixed dimension heterojunction. Here, 1D p-Te/2D n-Bi2Te3 heterojunctions are constructed by the simple and low-cost hydrothermal method. 1D p-Te/2D n-Bi2Te3 devices are applied in photoelectrochemical (PEC) photodetectors, with their high performance attributed to the good interfacial contacts reducing interface recombination. The device demonstrated a broad wavelength range (365–850 nm) with an/ph//dark as high as 377.45. The RiD*, and external quantum efficiency (EQE) values of the device were as high as 12.07 mA/W, 5.87 × 1010 Jones, and 41.05%, respectively, which were significantly better than the performance of the prepared Bi2Te3 and Te devices. A comparison of the freshly fabricated device and the device after 30 days showed that 1D p-Te/2D n-Bi2Te3 had excellent stability with only 18.08% decay of photocurrent. It is anticipated that this work will provide new emerging material for future design and preparation of a high-performance self-driven broadband photodetector. [ABSTRACT FROM AUTHOR]

Self-powered solar-blind ultraviolet photodetectors are considered for potential applications in secure communication and space detection. However, high-quality p-type wide bandgap semiconductors are nonexistent due to the self-compensation effect, which makes the design of p-n homojunction photodetectors a challenging proposition to date. In this work, a self-powered solar-blind ultraviolet photodetector is fabricated and discussed, based on a novel heterojunction of (InxGa1−x)2O3 ternary alloy films with two different compositions, which has a flexible design and can be easily fabricated for different applications. The heterojunction consists of an amorphous (In0.23Ga0.77)2O3 on the top of a bixbyite (In0.67Ga0.33)2O3 film prepared by radio frequency magnetron sputtering. The amorphous (In0.23Ga0.77)2O3/bixbyite (In0.67Ga0.33)2O3 heterojunction photodetector exhibits a responsivity of 5.78 mA/W, a detectivity of 1.69 × 1011 cm Hz1/2 W−1, and a high solar-blind UV (248 nm)/visible light (450 nm) rejection ratio of 1.39 × 103 at zero bias, suggesting decent spectral selectivity and high performance. The responsivity and peak wavelength of this photodetector can be tuned by the film thickness of the amorphous (In0.23Ga0.77)2O3. This work provides a new design for self-powered solar-blind UV detectors based on ternary alloy heterojunctions. [ABSTRACT FROM AUTHOR]

Encrypted optical communication is a critical technology in numerous fields, including remote sensing, environmental monitoring, and homeland defense. As a core of wireless interconnect systems, the conventional photodetectors generally receive optical signals from a single direction and fail to distinguish between various wavebands, severely undermining the potential for data transfer and protection. Herein, a Bi2O3 layer‐integrated waveband‐discriminated perovskite photodetector is presented. By rational design of energy band and device architecture, the novel photodetector is self‐powered, double‐sided responsive, and recognizable to the short or long‐wave UV, as well as visible optical signals. Without external bias, the device exhibits a high performance with peak responsivities of 42.1 and 72.3 mA W−1 in frontal and reverse incidence, respectively. Benefiting from these advantages, the photodetector is applicable to optical communication and encryption. In reverse incidence, reversible message delivery is achieved through the conversion and decoding of illumination patterns and binary digits. For a further step, the encrypted processing is fulfilled in frontal incidence. By virtue of the eight irradiation combinations, a secret key containing ten‐bit commands will generate over a billion encryption methods. This work realizes a new mode of communication and encryption that entirely relies on optical signals, offering new insights into wireless communication. [ABSTRACT FROM AUTHOR]

Films with excellent flexibility and mechanical stability are important for flexible and wearable devices. However, most films reported are prepared on substrates, and the synthesis of freestanding flexible films remains a challenge. Herein, a freestanding Bi2S3 nanofibrous membrane (NFM) is successfully prepared via a one‐step hydrothermal method, which is self‐assembled from ultralong Bi2S3 nanowires (NWs) over a length of millimeter‐scale crisscrossing each other. Significantly, the Bi2S3 NFM can be bent or clipped into an arbitrarily desired form. Based on the freestanding Bi2S3 NFM, an IR photodetector is fabricated, depicting a robust responsivity of 2.23 (2.06) µA W−1 under 850 (940) nm illumination. The Bi2S3 NFM photodetector exhibits a relatively fast response time (47.1 ms), which is attributed to high‐speed carrier transport efficiency in the NWs network. Under the bending states, the device still exhibits excellent detection performance, maintaining more than 86% of the initial photocurrent even after 1000 bending‐flattening times. The robust photoresponse of the Bi2S3 NFM photodetector after 2 months of storage in air and after 1 week in the bending state illustrates its excellent air stability and flexible detection ability. Besides, the photodetector can clearly identify the target image, indicating widespread potential applications in flexible and wearable fields. [ABSTRACT FROM AUTHOR]

The conventional forward‐structure perovskite devices typically employ organic small molecule and noble metal as the hole transport layer (HTL) and electrode, respectively, which results in poor thermal stability and high costs. To address this issue, a HTL‐free CH3NH3PbBr3 photodetector with the topological insulator bismuth telluride (Bi2Te3) electrode is developed. The device exhibits apparent sensitivity to ultraviolet/visible waveband with a peak responsivity of 97.5 mA W−1, switching ratio exceeding 104, and the detectivity is up to 1012 Jones without external bias. These figures‐of‐merit are distinguished among the reported CH3NH3PbBr3‐based devices. Impressively, this device presents a light power‐modulated near‐infrared detection thanks to the contribution of topological insulator Bi2Te3, and the underlying mechanism is elaborated in‐depth. Moreover, the novel device improves significantly in short and long‐time thermal stability. Benefiting from these distinguished properties, the photodetector is imaging‐capable and a 50 × 50 pixels' pattern with satisfactory resolution has been achieved. This work highlights the application of topological insulators on the HTL‐free perovskite photodetector, offering new insights for the future commercialization of perovskite devices. [ABSTRACT FROM AUTHOR]

Traditional photoelectrochemical-type (PEC-type) photodetectors have encountered several obstacles in practical application, such as the loss of photoelectrons due to interface charge recombination, short-term performance, and the problem of liquid electrolyte leakage. Herein, a novel quasi-solid-state polysulfide gel electrolyte (QSSPGE) is developed through the integration of liquid polysulfide into the polyvinyl alcohol (PVA) gel matrix. The PVA gel plays the dual function of passivating the surface trap states of bismuth telluride (Bi 2 Te 3) nanosheets and suppressing the leakage and volatilization of the liquid polysulfide electrolyte. Impressively, the PEC-type Bi 2 Te 3 photodetector based on the QSSPGE exhibits a boosted responsivity of 4.91 mA W−1 and a fast rise/decay time of 14/99 ms under 365 nm illumination, outperforming the responsivity (4.32 mA W−1) of PEC-type Bi 2 Te 3 photodetector based on liquid polysulfide. More importantly, the photocurrent density of the device remains at 95% and 81% of the initial value after being stored in air for one month and heated at 80 ℃ for 240 min, respectively, demonstrating excellent long-term stability and thermal stability. Additionally, the high-resolution imaging capacity of the device is demonstrated. This work provides an effective strategy for fabricating high-performance, stable PEC-type optoelectronic devices. [Display omitted] • A novel quasi-solid-state polysulfide gel electrolyte (QSSPGE) is developed. • Interface charge recombination between Bi 2 Te 3 and QSSPGE is suppressed. • Responsivity of the device is boosted from 4.32 mA W−1 to 4.91 mA W−1. • The device based on QSSPGE exhibits excellent thermal and long-term stability. • The stable imaging capacity of the device is demonstrated. [ABSTRACT FROM AUTHOR]

Ag@SnO2 nanoparticles (NPs) have been prepared by varying the concentration of sodium stannate trihydrate coated onto ZnO nanorods as the photoanode for photoelectrochemical self-powered ultraviolet photodetectors (UVPDs). Their structure, morphology, and optical properties were investigated. Compared with ZnO nanorods (NRs), the Ag@SnO2-coated ZnO NRs exhibited ultraviolet photoluminescence enhanced by nearly six orders of magnitude when 2 mL 40 mM sodium stannate trihydrate was used. This enhanced photoluminescence intensity is ascribed to the localized surface plasmon resonance of Ag in Ag@SnO2. Moreover, when varying the sodium stannate trihydrate concentration in the Ag@SnO2 NPs, the UVPD with 2 mL 40 mM sodium stannate trihydrate exhibited a high photocurrent density (Jsc) of 5.81 mA cm−2 compared with 2.34 mA cm−2 for the ZnO UVPD. This boost in Jsc is attributed to enhanced UV light harvesting and reduced charge recombination. Furthermore, this device also reached a high on/off ratio of 3885 and fast response time compared with the ZnO UVPD. Finally, such photoanodes formed from Ag@SnO2 nanoparticles coated on ZnO NRs are promising for use in photoelectrochemical-type self-powered UV photodetectors. [ABSTRACT FROM AUTHOR]

The development trend of modern electronics and optoelectronics is constantly moving towards highly integrated, comprehensive, and miniaturized devices. Vertical configuration provides an easy means to achieve higher integration density than traditional planar configuration, and possess higher carrier generation capabilities and transfer speed, which can further enhance the performance of optoelectronic devices. This technology holds tremendous potential for designing the next generation of electronic/optoelectronic devices. In this work, we developed a vertical heterojunction photodetector, which combines narrow-bandgap 2D topological insulator Bi 2 Se 3 , ultra-wide-bandgap amorphous Ga 2 O 3 , and high-performance p-Si substrate, achieving broad-spectrum detection from 254 to 1000 nm and significantly shortened response time due to the advantage of carrier vertical transmission. The response time of the device is less than 50 ms under illumination with different wavelengths. Moreover, the device exhibits self-powered characteristics, with maximum responsivity and detectivity of 0.175 mA/W and 1.58 × 1010 Jones, respectively, under 365 nm light irradiation at zero bias. A switch ratio as high as 10 3 is demonstrated under 365 and 470 nm illumination, highlighting the high performance of device. Additionally, the device displays excellent stability and imaging capability. Our research provides a promising and instructive prospect for the practical application of vertical broadband self-powered heterojunction PDs in a wider range of fields. • A vertical self-powered Bi 2 Se 3 /a-Ga 2 O 3 /p-Si heterojunction PD was achieved. • The device showed broadband response (254–1000 nm) and imaging ability. • Switch ratio as high as 103 under 365 and 470 nm illumination was presented. [ABSTRACT FROM AUTHOR]

All-inorganic metal halide perovskite is considered as one of the most promising perovskite materials for photodetectors, because of its remarkable optoelectronic characteristics and stability. Whereas, it remains challenge to achieve both excellent photodetection performance and stability due to the multitudes of defects in perovskite films. Herein, an interface engineering based on surface passivation strategy to achieve high-quality CsPbBr 3 perovskite films by introducing thioacetamide (C 2 H 5 NS, abbreviated as TAA) as interface materials is reported. The interaction between TAA and perovskite passivates the uncoordinated Pb2+ on the surface of CsPbBr 3 film, suppress carrier non-recombination and accelerates carriers transfer. The self-powered photodetector based on the passivated CsPbBr 3 film prefers the maximum responsivity of 0.26 A W−1 and detectivity of 8.39 × 1012 Jones under 520 nm irradiation. In addition, the optimized photodetector exhibits excellent stability and maintains more than 98% of its initial photocurrent when operating over 8 h. This work demonstrates an alternative approach for the preparation of improved performance in CsPbBr 3 perovskite photodetectors and associated photoelectric devices. [Display omitted] • Introducing thioacetamide into the perovskite device as interface layer. • The device is self-powered, high-detectivity and rapidly detection to radiation. • The device achieved a champion responsivity of 0.26 A/W with excellent stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • The thioacetamide can effective passivate under-coordinated Pb2+ defects. • The device is self-powered, high-detectivity and rapidly detection to radiation. • The device achieved a champion responsivity of 0.39 A/W with excellent stability. • A clear and discernible image with high fidelity is achieved by employing the device. All-inorganic perovskite photodetectors aroused widespread attention due to the splendid photoelectric characteristics and stability. However, the inherent defects in perovskite films hinders the progress of the photodetectors. Here, a Lewis base of thioacetamide additive was used to passivate defects in CsPbBr 3 perovskite films based on Lewis acid-base interactions. The quality of the film has been distinctly enhanced due to the interaction between the S donor in thioacetamide and the uncoordinated Pb2+ in perovskite, diminishing the defect state density and inhibits the non-radiative recombination. The self-powered champion device based on CsPbBr 3 film contain optimum thioacetamide additive exhibits a lower dark current density of 4.01 nA/cm2, a peak responsivity of 0.39 A/W, a rapid rise/decay time of 12.4 μs/56.2 μs, a peak detectivity of 1.08 × 1013 Jones and a lager linear dynamic range of 99 dB, which are much better than photodetector based on CsPbBr 3 perovskite without TAA additive. Furthermore, it exhibits high-resolution imaging sensing capability at zero bias. This research affords guidance for the performance improvement and application of all-inorganic perovskite photodetectors. [ABSTRACT FROM AUTHOR]

ZnO nanorods (NRs) have been successfully fabricated on p-type boron-doped diamond (BDD) substrate by hydrothermal method. The current-voltage characteristics of the ZnO NRs/BDD heterojunction show a typical rectifying behavior with extremely low reverse leakage current and high rectification ratio of around 370 at bias of 3 V. Exposed to ultraviolet (UV) illumination with a wavelength of 365 nm, the time dependent photoresponse manifests high sensitivity and consistent transients with a rise time of 4.9 s and decay time of 6.4 s. Circulating on/off measurement under UV detection demonstrates the excellent stability and repeatability for as-fabricated ZnO NRs/BDD heterojunction. Furthermore, the mechanism for UV detection on the ZnO NRs/BDD heterojunction has also been discussed. [ABSTRACT FROM AUTHOR]

• MAPbCl 3 and amorphous Ga 2 O 3 formed a hybrid structure for the first time. • The responsivity enhanced nearly 70 times by inserting the amorphous Ga 2 O 3 layer. • The MAPbCl 3 /amorphous Ga 2 O 3 photodetector is sensitive with high-detectivity. • The performance of polycrystalline detector is comparable to single crystal device. • The detector is self-powered and realizes accurate detection of UVA radiation. [Display omitted] UVA radiation can survive from the absorption of atmospheric layer and reaches the terrestrial surface, which is harmful to human eyes, blood vessels, and elastic fibers. It is meaningful to detect the UVA radiation precisely. A sensitive, high-detectivity and self-powered UVA detector based on polycrystalline CH 3 NH 3 PbCl 3 /amorphous Ga 2 O 3 hybrid structure is presented in this work. Under zero bias, the rise/decay time of the photodetector are 56/67 ms, and the detectivity reaches up to 5.4 × 1010 Jones. The performance is even superior to most of the reported devices based on CH 3 NH 3 PbCl 3 single crystal. The heterojunction between amorphous Ga 2 O 3 and CH 3 NH 3 PbCl 3 accelerates the separation of photon-generated carrier and effectively reduces the recombination. In addition, the high resistivity and low surface roughness of the amorphous Ga 2 O 3 layer also contribute to the improvement of device parameters. This study offers new insights to improve the polycrystalline MAPbCl 3 devices by ultra-wide bandgap amorphous semiconductors. [ABSTRACT FROM AUTHOR]

[Display omitted] The detection and quantification of UVA radiation are indispensable for the reason that excess UVA radiation is harmful to skin, eyes, immune system and blood vessels of the human body. This study demonstrates a high-performance and accurate UVA (320–400 nm) detector based on polycrystalline CH 3 NH 3 PbCl 3 /α-Ga 2 O 3 nanorod array hybrid structure, which was fabricated by using facile and low-cost solution processing method. The devices show the maximum responsivity of 8.02 mA/W under zero bias, which is two orders of magnitude larger than bare polycrystalline CH 3 NH 3 PbCl 3 photodetector, as well as high speed photo-switching. Meanwhile, the detectivity of this self-powered device reaches up to 1.9 × 1011 Jones, which is even superior to most of the reported single-crystal CH 3 NH 3 PbCl 3 photodetectors. This study reveals the potential in the combination of ultra-wide bandgap inorganic semiconductors with polycrystalline organic–inorganic hybrid perovskites in high performance of photodetector and other optoelectronic devices. [ABSTRACT FROM AUTHOR]

Films with honeycomb‐like structures have became ideal network structures for the development of flexible photodetectors due to their superior mechanical stability and merits in large active surface area, high carrier transport efficiency and well light absorption capacity. In this work, a honeycomb‐like Bi2S3 film with centimeter‐scale (2 cm × 2 cm) is synthesized on an ultrathin flexible fluorophlogopite mica substrate, which consists of a well‐stabilized arrangement of triangular unit structures forming an interconnected network structure. Based on the as‐grown honeycomb‐like Bi2S3 film, a flexible photodetector with a broadband response from ultraviolet to infrared is constructed, which displays the highest responsivity (Rλ) of 611.2 mA W−1 and specific detectivity (D*) of 4.77 × 1010 Jones. And at 850 nm light illumination, there is nearly no deterioration in Rλ and D* of the Bi2S3 flexible photodetector after successive multiple bends, benefiting from the excellent structural stability of the triangular honeycomb network structure. Notably, the device maintains excellent detection performance after 1 week of prolonged bending in air without any encapsulation, and its photocurrent can still reach 90.39% of the initial photocurrent. In addition, the device also exhibits favorable durability, cycle stability, as well as high‐definition imaging ability in bending state and after bending recovery. [ABSTRACT FROM AUTHOR]

The investigation of photodetectors with broadband response and high responsivity is essential. Zinc Oxide (ZnO) nanowire has the potential of application in photodetectors, owing to the great optoelectrical property and good stability in the atmosphere. However, due to a large number of nonradiative centers at interface and the capture of surface state electrons, the photocurrent of ZnO based photodetectors is still low. In this work, 2D Bi2Se3/ZnO NWAs heterojunction with type-I band alignment is established. This heterojunction device shows not only an enhanced photoresponsivity of 0.15 A/W at 377 nm three times of the bare ZnO nanowire (0.046 A/W), but also a broadband photoresponse from UV to near infrared region has been achieved. These results indicate that the Bi2Se3/ZnO NWAs type-I heterojunction is an ideal photodetector in broadband detection. [ABSTRACT FROM AUTHOR]

In this work, FTO/amorphous-(In 0.23 Ga 0.77) 2 O 3 /spiro-OMeTAD photodetector capable of broadband detection (200–400 nm) with wavelength discrimination is fabricated. Incorporation of spiro-OMeTAD as hole transport layer improved self-powered performance of FTO/amorphous-(In 0.23 Ga 0.77) 2 O 3 /spiro-OMeTAD broadband photodetector. Under 260 nm illumination, the photodetector exhibited a responsivity (R) of 0.63 mA/W and a detectivity (D *) of 5.40 × 1010 cm Hz1/2 W−1 under zero bias. The values enhanced to R = 0.61 mA/W and D * = 5.50 × 1010 cm Hz1/2 W−1 under 320 nm illumination. For 400 nm illumination, the values were R = 0.35 mA/W, D * = 4.90 × 1010 cm Hz1/2 W−1 under zero bias. Moreover, FTO/amorphous-(In 0.23 Ga 0.77) 2 O 3 /spiro-OMeTAD photodetector demonstrated faster response speed with rising time decreased to 0.02 s and decay time decreased to 0.04 s, compared to FTO/amorphous-(In 0.23 Ga 0.77) 2 O 3 photodetectors under 260 nm illumination. The wavelength discrimination capability within 200–400 nm range was attributed to type-I staggered band alignment in FTO/amorphous-(In 0.23 Ga 0.77) 2 O 3 interface and type-Ⅱ staggered band alignment in spiro-OMeTAD/amorphous-(In 0.23 Ga 0.77) 2 O 3 interface, through choosing illumination on FTO or spiro-OMeTAD sides. In conclusion, FTO/amorphous-(In 0.23 Ga 0.77) 2 O 3 /spiro-OMeTAD heterogeneous junction, using a combination of p-type polymer and inorganic wide bandgap semiconductors, shows great potential for self-powered and high-performance broadband photodetectors. [ABSTRACT FROM AUTHOR]

Due to their high performance, photoelectrochemical ultraviolet (UV) photodetectors have attracted much attention, but the recombination of photogenerated electrons at the interface of photoanode/electrolyte limited further improvement of photoelectrochemical UV photodetectors (PEC UVPDs). Modification of TiO2 photoanode by SrTiO3 could improve the performance of UVPD, because the energy barrier that is established at the TiO2–SrTiO3 interface could accelerate the separation of the photogenerated electrons-holes pair. However, the recombination center that is caused by the preparation of TiO2@SrTiO3 core-shell heterostructured nanostructure decreases the performance of PEC UVPDs, which is still an important problem that hindered its application in PEC UVPDs. In this paper, we presented a Sr-doped free TiO2@SrTiO3 core-shell heterostructured nanowire arrays as a photoanode for the self-powered PEC UVPD. This will not only accelerate the separation of the photogenerated electrons-holes pair, but it will also reduce the recombination of photogenerated electron-hole pairs in the photoanode. The intrinsic effect of SrTiO3 reaction time on the J variations of UVPDs is investigated in detail. An impressive responsivity of 0.358 A·W−1 was achieved at 360 nm for the UVPD based on TiO2@SrTiO3 core-shell heterostructured nanowire arrays, which heretofore is a considerably high photoresponsivity for self-powered photoelectrochemical UVPDs. Additionally, this UVPD also exhibits a high on/off ratio, fast response time, excellent visible-blind characteristic, and linear optical signal response. [ABSTRACT FROM AUTHOR]

[Display omitted] • Large-scale Bi 2 O 3 /Ag/TiO 2 nanotubes (BAT NTs) were successfully synthesized through the facile solution process at room temperature. • BAT NTs ultraviolet photodetector (UVPD) exhibits satisfactory photodetection performance with a fast response speed of 25 ms. • BAT NTs UVPD features excellent environmental stability after 1 month and cycling stability for 100 switching cycles. • BAT NTs UVPD achieves high-resolution imaging results with "UV" pattern and performs precise UV optical communication under zero bias. Large-scale Bi 2 O 3 /Ag/TiO 2 nanotubes (BAT NTs) were successfully synthesized using ZnO nanorods template through the facile solution process at room temperature. Highly ordered BAT NTs with an average diameter of approximately 300 nm were arranged hierarchically on the overall ITO substrate. In addition, a self-powered UV photodetector (UVPD) based on BAT NTs was assembled and the photoresponse characteristics were investigated under a wide range of UV light intensity. The BAT NTs UVPD exhibits satisfactory UV photodetection performance with detectivity of 1.55 × 1010 Jones and on/off ratio exceeding 103, associated with a fast response speed of 25 ms, which is ascribed to the efficient carrier transport inspired by the 1D structure and energy band structure. In addition, BAT NTs UVPD also features excellent environmental stability and long cycling stability. Benefitting from the desirable properties, the BAT NTs UVPD achieves high-resolution imaging results with "UV" pattern as a single pixel unit and performs accurate UV optical communication as a signal receiver at zero bias. Eventually, the detailed self-powered UV detection mechanism for BAT NTs UVPD was illustrated. [ABSTRACT FROM AUTHOR]

Homogeneous and large-scale Bi 2 O 3 nanospheres (NSs) were successfully prepared using a one-step hydrothermal route. It is noticed that the Bi 2 O 3 NSs were dominated by the spherical shape covered by convex bulges, where the average diameter ranged from 100 to 200 nm. After that, the Bi 2 O 3 NSs were used to fabricate the ultraviolet photodetector (UVPD) with self-powered feature. After being illuminated with UV light of 365 nm, the response time of the Bi 2 O 3 NSs UVPD can reach up to ∼26 ms, and the detectivity achieved 1.77 × 109 Jones, associated with on/off ratio of more than 103. The temporal stability after storage in air for 1 month and the long cycle stability of 100 cycles both confirmed the robust stability of Bi 2 O 3 NSs, and the photocurrent can still reach 98.5% of the initial value for 100 cycles. Moreover, high-resolution image with Chinese characters of "Ha Gong Da" was well acquired under 365 nm light irradiation, which confirmed the fast light extraction capability and high dynamic range of the device. Furthermore, the detection mechanism of the Bi 2 O 3 NSs UVPD was also discussed. • Large-scale convex Bi 2 O 3 nanospheres (NSs) were synthesized adopting a facile one-step synthesis strategy. • Bi 2 O 3 NSs ultraviolet photodetector (UVPD) displays fast response time and large on/off ratio at zero bias under UV light. • Bi 2 O 3 NSs UVPD features robust temporal stability after 1 month and long cycle stability for 100 cycles. • Bi 2 O 3 NSs UVPD can achieve high-resolution images and exhibit fast light extraction capability and high dynamic range. [ABSTRACT FROM AUTHOR]

[Display omitted] • Large-area Bi 2 O 2 Se film composed of many single crystal nanosheets was synthesized. • The layered Bi 2 O 2 Se film features a sharp interface with the SrTiO 3 substrate. • Bi 2 O 2 Se photodetector exhibits excellent cycling stability and long-term stability. • Bi 2 O 2 Se photodetector displays good imaging capability and rapid light extraction. Two-dimensional (2D) materials have proven to be a highly promising candidate for applications in electronic and optoelectronic devices due to their attractive structure and properties. However, the micron-scale dimensions, random distribution on the substrate, and complex transfer processes of 2D materials inevitably cause difficulties in device integration, which limits practical applications in photodetection. Herein, high-quality 2D Bi 2 O 2 Se film (2×2 cm) composed of numerous single crystal nanosheets on SrTiO 3 substrate was prepared employing the chemical vapor deposition method. The layered Bi 2 O 2 Se film features a perfect atomic alignment free of lattice mismatch and a sharp interface with the SrTiO 3 substrate. Afterward, a broadband photodetector based on 2D Bi 2 O 2 Se film was directly constructed, which covered the ultraviolet, visible and infrared range from 365 to 940 nm and demonstrated a fast response speed of 32 ms and 44 ms, maximum responsivity and detectivity of 136 mA/W and 2×109 Jones. Importantly, fast on/off behavior for 100 cycles and reliable photoresponse after storage in air for 1 year confirmed the excellent cycling stability and air stability of the Bi 2 O 2 Se photodetector. Furthermore, the Bi 2 O 2 Se photodetector as a single point sensing pixel was capable to perform high-resolution imaging of "H, I, T" patterns. This research affirms the huge potential of Bi 2 O 2 Se photodetectors to perform as reliable multi-band detection units in complex systems. [ABSTRACT FROM AUTHOR]

Massive two-dimensional (2D) Bi 2 O 3 nanosheets (NSs) were synthesized adopting a facile solution route. It can be distinctly perceived that the average dimension of the Bi 2 O 3 NSs was mainly centered in the range of 1–2 μm and the thickness reached about 110 nm. Afterward, the self-powered ultraviolet photodetector (UVPD) was successfully prepared established on the 2D Bi 2 O 3 NSs, which exhibited high photosensitivity and robust stability in exposure to UV light, accompanied with the fast rise time of ∼33 ms and decay time of ∼47 ms. In addition, the Bi 2 O 3 NSs UVPD could perform a stable operation over a wide range of UV light intensities. Moreover, the photodetection mechanism for the Bi 2 O 3 NSs UVPD was also illustrated. • Massive two-dimensional Bi 2 O 3 nanosheets were synthesized adopting a facile solution route. • Exposure to UV light, Bi 2 O 3 nanosheets UV photodetector exhibited high photosensitivity free of the external power. • Bi 2 O 3 nanosheets UV photodetector could perform stable operation over the wide range of UV light intensities. [ABSTRACT FROM AUTHOR]

Currently, bismuth oxychalcogenide family (Bi 2 O 2 X, X S, Se, Te), led by Bi 2 O 2 Se with unique characteristics, have emerged as promising candidates for high-performance optoelectronic devices. Herein, the novel Bi 2 O 2 S flowers with hierarchical structure have been successfully prepared via a facile hydrothermal method with only 3 h of reaction. The as-prepared Bi 2 O 2 S flower is composed of many ultrathin nanosheets (NSs) with a thickness of about 12–16 nm. And the possible formation mechanism of ultrathin NSs self-assembled Bi 2 O 2 S flowers is further analyzed. In addition, a self-powered infrared photodetector based on Bi 2 O 2 S flowers, which can work without an external power, is designed. Under illumination at 850 nm light, the Bi 2 O 2 S flowers photodetector exhibits well photoresponse switching behaviors, of which the high responsivity, specific detectivity and fast response time reach up to 9.48 mA/W, 9.96 × 1010 Jones and 227.7 ms, respectively. Of particular note, the Bi 2 O 2 S flowers photodetector also possesses the eximious stability. [Display omitted] ● The Bi 2 O 2 S flowers composed of 2D ultrathin nanosheets were prepared on the fluorine-doped tin oxide substrate. ● The Bi 2 O 2 S flowers infrared photodetector exhibits a high responsivity of 9.48 mA/W and detectivity of 9.96 × 1010 Jones. ● The Bi 2 O 2 S flowers infrared photodetector possesses eximious stability, and can operated without an external power source. [ABSTRACT FROM AUTHOR]

[Display omitted] • Large-scale Bi 2 O 3 nanotubes (NTs) arrays were successfully synthesized on ITO substrate employing ZnO nanorods. • An ultraviolet photodetector based on Bi 2 O 3 NTs was fabricated to show fast response speed and good cycling stability. • Bi 2 O 3 NTs ultraviolet photodetector could realize accurate UV detection free of external power. Large-scale Bi 2 O 3 nanotubes (NTs) arrays were successfully synthesized on ITO substrate with the assistance of ZnO nanorods template at room temperature. The as-synthesized highly orientated Bi 2 O 3 NTs with an average diameter of ∼95 nm were well distributed throughout the entire substrate. Moreover, Bi 2 O 3 NTs were employed to construct the ultraviolet photodetector (UVPD). Received to UV irradiation, the Bi 2 O 3 NTs UVPD displayed a high average current density of 40.4 μA/cm2, coupled with fast average rise time of ∼28.8 ms and decay time of ∼40.9 ms. Furthermore, the Bi 2 O 3 NTs UVPD could carry out accurate UV detection without external bias as well as maintain good stability and repeatability. Additionally, the UV detection mechanism of the as-assembled Bi 2 O 3 NTs UVPD was also discussed. [ABSTRACT FROM AUTHOR]

Large-area octahedral Bi 2 O 3 nanoblocks (NBs) have been successfully fabricated on ITO substrate through a facile hydrothermal synthesis. The Bi 2 O 3 NBs with an average diameter of ∼2 μm were homogeneously grown over the entire surface of the substrate. Furthermore, the ultraviolet photodetector (UVPD) was assembled based on the Bi 2 O 3 NBs. On exposure to UV light, the photocurrent density of Bi 2 O 3 NBs UVPD surged to 38.5 μA/cm2, associated with rapid rise and decay time of ∼27.7 ms and ∼27.2 ms respectively. Especially, the as-fabricated detector could achieve stable UV detection free of the power supply and exhibit good stability and reusability. Moreover, the growth mechanism of the Bi 2 O 3 NBs and detection mechanism of the Bi 2 O 3 NBs UVPD have been investigated. [ABSTRACT FROM AUTHOR]