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The field of next‐generation microdisplays is flourishing. Relevant display technologies, such as mini‐light emission diodes (mini‐LEDs), micro‐organic light emission diodes (micro‐OLEDs), and micro‐light emission diodes (micro‐LEDs) are thus in the urgent stage of development. From this perspective, comprehensive and systematical analyzes are conducted for the aforesaid microdisplay configurations. A holistic view of microdisplay technologies is developed with the corresponding performance metrics, providing a path for miscellaneous scenarios. Among these scenarios, the applications in augmented reality (AR), virtual reality (VR), wearable devices, and head‐up displays (HUD) are currently attracting considerable attention for deeper human‐digital interactions. However, there is a multiplicity of obstacles and challenges hindering such development. Nevertheless, recent advances in microdisplay technologies hold tremendous promise for the paradigms of these applications, taking a leap forward for next‐generation microdisplays. This review presents perspectives, relevant materials, and the technology landscape for such ongoing display technologies, offering guidance on the design of advanced microdisplays. [ABSTRACT FROM AUTHOR]

Aluminum Gallium Nitride (AlGaN) ultraviolet‐C (UV‐C) micro‐light‐emitting diodes (microLEDs) offer significant advantages in terms of convenience, cost‐effectiveness, and environmental friendliness, positioning them as promising candidates for display applications. However, achieving the desired high efficiency and scalability for large displays with ultra‐fine pixels necessitates substantial progress beyond current experimental outcomes. This study showcases the application of AlGaN UV‐C microLED display panels and micro‐displays incorporating quantum dots (QDs) for color conversion. Sidewall treatment and atomic layer deposited (ALD) passivation effectively address dangling bonds and etching damages, leading to a notable enhancement of TM‐polarized light extraction efficiency (LEE). Moreover, dedicated strain modulation efforts successfully reduce the high Al content (over 50%) wafer bowling effect, facilitating the modularization of ultrafine‐pitch AlGaN UV‐C microLED panels. Consequently, the devices achieve a peak performance of over 5% external quantum efficiency (EQE) as the mesa size scales down to 3 μm. The highlighted 0.18‐inch UV‐C microLED display panels, featuring a 9 μm pixel size, are precisely controlled by a CMOS IC driver to achieve desired patterns. Serving as an efficient pumping source for perovskite quantum dots paper (PQDP), this UV‐C microLED display suggests the potential to revolutionize the full‐color display industry by providing an innovative and unconventional solution. [ABSTRACT FROM AUTHOR]

Aluminum Gallium Nitride (AlGaN) ultraviolet‐C (UV‐C) micro‐light‐emitting diodes (microLEDs) offer significant advantages in terms of convenience, cost‐effectiveness, and environmental friendliness, positioning them as promising candidates for display applications. However, achieving the desired high efficiency and scalability for large displays with ultra‐fine pixels necessitates substantial progress beyond current experimental outcomes. This study showcases the application of AlGaN UV‐C microLED display panels and micro‐displays incorporating quantum dots (QDs) for color conversion. Sidewall treatment and atomic layer deposited (ALD) passivation effectively address dangling bonds and etching damages, leading to a notable enhancement of TM‐polarized light extraction efficiency (LEE). Moreover, dedicated strain modulation efforts successfully reduce the high Al content (over 50%) wafer bowling effect, facilitating the modularization of ultrafine‐pitch AlGaN UV‐C microLED panels. Consequently, the devices achieve a peak performance of over 5% external quantum efficiency (EQE) as the mesa size scales down to 3 μm. The highlighted 0.18‐inch UV‐C microLED display panels, featuring a 9 μm pixel size, are precisely controlled by a CMOS IC driver to achieve desired patterns. Serving as an efficient pumping source for perovskite quantum dots paper (PQDP), this UV‐C microLED display suggests the potential to revolutionize the full‐color display industry by providing an innovative and unconventional solution. [ABSTRACT FROM AUTHOR]

Underwater optical communication (UOC) has attracted considerable interest in the continuous expansion of human activities in marine/ocean environments. The water‐durable and self‐powered photoelectrodes that act as a battery‐free light receiver in UOC are particularly crucial, as they may directly face complex underwater conditions. Emerging photoelectrochemical (PEC)‐type photodetectors are appealing owing to their intrinsic aqueous operation characteristics with versatile tunability of photoresponses. Herein, a self‐powered PEC photodetector employing n‐type gallium nitride (GaN) nanowires as a photoelectrode, which is decorated with an iridium oxide (IrOx) layer to optimize charge transfer dynamics at the GaN/electrolyte interface, is reported. Strikingly, the constructed n‐GaN/IrOx photoelectrode breaks the responsivity‐bandwidth trade‐off limit by simultaneously improving the response speed and responsivity, delivering an ultrafast response speed with response/recovery times of only 2 µs/4 µs while achieving a high responsivity of 110.1 mA W−1. Importantly, the device exhibits a large bandwidth with 3 dB cutoff frequency exceeding 100 kHz in UOC tests, which is one of the highest values among self‐powered photodetectors employed in optical communication system. [ABSTRACT FROM AUTHOR]

The elementary electronic‐logic‐gates, performing basic logic functions using electric signals as input, act as a building block of modern digital circuits. Intriguingly, the optoelectronic‐logic‐gates (OLGs), composed of optical devices, are emerging as a new logic platform which enables faster and large‐capacity data transmission and processing by using photons as input. However, the strict operation principle of classic optical devices, for example, the unidirectional photoresponse of the photodetector, restricts the functional enrichment of OLGs. Herein, reprogrammable OLGs in a photoelectrochemical (PEC)‐environment are reported by employing gallium‐nitride semiconductor p–n nanowires as photoelectrodes where bidirectional photocurrent is achieved, leading to the demonstration of various binary OLGs including "NOT", "XOR", and "OR". Strikingly, thanks to the versatile tunability of PEC‐photoelectrodes, the logic function of these OLGs is switchable by simply adjusting programming inputs including light intensity, bias voltage, electrolyte condition, and the physicochemical properties of the nanowire surface. Most importantly, unique ternary OLGs, for example, ternary "OR" gates, can also be realized based on binary ones by just tuning their applied bias for higher logic complexity applications, without changing the device architecture. Such reprogrammable binary and ternary OLGs could provide a new avenue toward next‐generation logic circuits for fast computing and data‐processing in the future. [ABSTRACT FROM AUTHOR]

In the past few years, nanocellulose, as a new‐emerging colloid, has developed into a large family and gained increasing attention owing to its favorable properties. It represents a ubiquitous feature in electronics as different components according to principles extend across energy, lighting management, and transistors and biosensors to information technologies. Within these decades, there are a lot of remarkable phenomena, effects, and performances relevant to a few additional attributes of nanocellulose, making the electronics perform better and better. Toward the rapid nanotechnology development and the need of the society, characterizing this important nanomaterial and making more and more new electronics have become important things to be done. This review consolidates the contribution of nanocellulose to nano‐related electronics, summarizes these methods to utilize nanocellulose as any component in devices, and points out the attributes of the nanocellulose. In the devices, the recent advances into solid‐state electronics, optoelectronic devices, and flexible/wearable electronics are categorized. The intrinsic electrical, dielectric and electronic structures, and properties of nanocellulose related to the device performances are particularly summarized and analyzed, which is believed beneficial in providing a judgment criterion for devices in the future. [ABSTRACT FROM AUTHOR]

Developing a green and energy‐saving alternative to the traditional Haber‐Bosch process for converting nitrogen into ammonia is urgently needed. Imitating from biological nitrogen fixation and photosynthesis processes, this work develops a monolithic artificial leaf based on triple junction (3J) InGaP/GaAs/Ge cell for solar‐driven ammonia conversion under ambient conditions. A gold layer serves as the catalytic site for nitrogen fixation with photogenerated electrons. The Au/Ti/3J InGaP/GaAs/Ge photoelectrochemical (PEC) device achieves high ammonia production rates and Faradaic efficiencies in a two‐electrode system without applying external potential. For example, at 0.2 sunlight intensity, the solar‐to‐ammonia (STA) conversion efficiency reaches 1.11% and the corresponding Faradaic efficiency is up to 28.9%. By integrating a Ni foil on the anode side for the oxygen evolution reaction (OER), the monolithic artificial leaf exhibits an ammonia production rate of 8.5 µg cm−2 h at 1.5 sunlight intensity. Additionally, a 3 × 3 cm unassisted wireless PEC device is fabricated that produces 1.0039 mg of ammonia in the 36‐h durability test. Thus, the new artificial leaf can successfully and directly convert solar energy into chemical energy and generate useful products in an environmentally friendly approach. [ABSTRACT FROM AUTHOR]

Hydrogen, produced through a zero‐pollution, sustainable, low‐cost, and high‐efficiency process, is regarded as the "ultimate energy" of the 21st century. Solar water‐splitting techniques have immense potential to make the idea a reality. Two promising approaches, photovoltaic‐electrolysis (PV‐EC) and photoelectrochemistry (PEC), have demonstrated solar‐to‐hydrogen conversion efficiency over 10%, which is the minimum required for competitively priced, large‐scale systems. Extensive studies of PV‐EC and PEC devices reported within the past five decades show increasing design complexity. To accurately describe the gap between laboratory research and practical application, the basic principles and concepts of PV‐EC and PEC are elaborated and clarified. The history of these developments is systematically summarized, and a comprehensive techno‐economic analysis of PV‐EC and PEC solar hydrogen production of 10 000 kg H2 day−1 is performed. The analysis shows that no solar hydrogen system is currently competitive with production methods based on fossil fuels, but the development of high‐efficiency water‐splitting electrolyzers with cost‐competitive components (especially for cation/anion exchange membranes) can accelerate progress. [ABSTRACT FROM AUTHOR]

The commercialization of μ‐LED displays is impeded by the persistent obstacle of full‐color representation, particularly when the pixel pitch is scaled down to below 20 µm. The utilization of quantum dots (QDs) as color converters has proven effective in mitigating this limitation. To this end, this study proposes the use of perovskite quantum dots papers (PQDPs) as color converters for μ‐LEDs, intending to achieve full‐color display functionality. [ABSTRACT FROM AUTHOR]

Micro‐light‐emitting diodes (Micro‐LEDs) based on gallium nitride (GaN) materials offer versatile platforms for various applications, including displays, data communication tools, photodetectors, and sensors. In particular, the introduction of Micro‐LEDs in the optoelectronic industry enables the development of novel short‐distance wireless communication applications for the Internet of Things as well as near‐to‐eye displays for virtual reality and augmented reality. Micro‐LEDs used in conjunction with colloidal quantum dots (QDs) as color‐conversion layers provide efficient full‐color displays as well as white LEDs for high‐speed visible light communications (VLCs). Here, the latest progress on full‐color Micro‐LED displays with a printed QD color conversion layer, GaN material‐based Micro‐LEDs for VLC systems, and the photostability of novel QD materials for Micro‐LEDs is comprehensively reviewed. Outlooks on the efficiency of Micro‐LEDs with sizes ≤10 µm, QD stability issues, and flexible Micro‐LED displays are also provided. [ABSTRACT FROM AUTHOR]

Multiple‐band and spectrally distinctive photodetection play critical roles in building next‐generation colorful imaging, spectroscopy, artificial vision, and optically controlled logic circuits of the future. Unfortunately, it remains challenging for conventional semiconductor photodetectors to distinguish different spectrum bands with photon energy above the bandgap of the material. Herein, for the first time, a photocurrent polarity‐switchable photoelectrochemical device composed of group III‐nitride semiconductors, demonstrating a positive photocurrent density of 10.54 µA cm−2 upon 254 nm illumination and a negative photocurrent density of −0.08 µA cm−2 under 365 nm illumination without external power supply, is constructed. Such bidirectional photocurrent behavior arises from the photovoltage‐competing dynamics across two photoelectrodes. Importantly, a significant boost of the photocurrent and corresponding responsivity under 365 nm illumination can be achieved after decorating the counter electrode of n‐type AlGaN nanowires with platinum (Pt) nanoparticles, which promote a more efficient redox reaction in the device. It is envisioned that the photocurrent polarity‐switch behavior offers new routes to build multiple‐band photodetection devices for complex light‐induced sensing systems, covering a wide spectrum band from deep ultraviolet to infrared, by simply engineering the bandgaps of semiconductors. [ABSTRACT FROM AUTHOR]

The intriguing surface sensitivity of the single‐crystalline semiconductor nanowires offers tremendous opportunity in tuning the physical properties of nanophotonic and nanoelectronic devices for versatile applications. Particularly, in the pursuit of emerging photoelectrochemical (PEC)‐type devices, significant efforts have been devoted to understanding the charge transfer dynamics between the nanowires and the electrolyte. Here, a PEC‐type ultraviolet photodetector consisting of GaN p‐n junction nanowires as photoelectrodes is constructed. It is found that two competing charge transport processes at the nanowires' surface as well as in the p‐n junction co‐determine the photoresponsive behavior of the device. Furthermore, the surface platinum (Pt) decoration has successfully tuned the charge transfer dynamics by enhancing the charge transport efficiency at the surface, resulting in a twenty‐fold increase of the photocurrent compared to the pristine GaN nanowires. Theoretical calculations reveal that the newly formed electronic states at the Pt/GaN interface account for the improved charge transfer at the surface, and the optimal hydrogen adsorption energy contributes to the boosted PEC reaction rate. The synergy of these two effects uncover the underlying mechanism of the high photoresponse of the constructed Pt/GaN‐nanowires‐based PEC photodetectors. [ABSTRACT FROM AUTHOR]

The extraordinary electronic, optical, and mechanical characteristics of 2D materials make them promising candidates for optoelectronics, specifically in infrared (IR) detectors owing to their flexible composition and tunable optoelectronic properties. This review presents the recent progress in IR detectors composed of 2D materials and their hybrid structures, including graphene, black phosphorous, transition metal dichalcogenides, halide perovskite as well as other new layered materials and their heterostructures. The focus is on the short‐wave, mid‐wave, and long‐wave infrared regimes, which pose a grand challenge for rational materials and device designs. The dependence of the device performance on the optical and electronic properties of 2D materials is extensively discussed, aiming to present the general strategies for designing optoelectronic devices with optimal performance. Furthermore, the recent results on 2D material‐based heterostructures are presented with an emphasis on the relationship between band alignment, charge transfer, and IR photodetection. Finally, a summary is given as well as the discussion of existing challenges and future directions. [ABSTRACT FROM AUTHOR]

Searching for power‐independent, compact, and highly environment‐sensitive photodetectors is a critical step towards the realization of next‐generation energy‐efficient and sustainable integrated optoelectronic systems. Particularly, the deep ultraviolet (UV) band, which has large photon energy, is extremely suitable for environment monitoring and invisible light communication application. Herein, the demonstration of self‐powered deep UV solar‐blind photodetectors in a photoelectrochemical (PEC) cell configuration is reported, adopting wide bandgap n‐type aluminum gallium nitride (AlGaN) nanowires as photoelectrode. After decorating nanowires with noble metal ruthenium (Ru), the constructed solar‐blind PEC photodetectors exhibited excellent responsivity of 48.8 mA W‐1, fast response speed (rise time of 83 ms and decay time of 19 ms) with large photocurrent density of 55 μA cm‐2 at 254 nm illumination. Such superior performance can be attributed to, firstly and foremost, the successful synthesis of highly uniform and defect‐free n‐type AlGaN nanowires which ensures efficient photogeneration via effective light‐harvesting, and secondly, the boosted carrier separation and collection efficiency through Ru decoration. This novel nanoarchitecture enables deep UV photodetection to work stably with low energy consumption, intriguingly, opening the possibility for the development of high‐performance PEC photodetectors based on group III‐nitride semiconductors covering the entire spectral range from infrared to deep UV. [ABSTRACT FROM AUTHOR]

Due to the potential applications in optoelectronic memories, optical control of ferroelectric domain walls has emerged as an intriguing and important topic in modern solid‐state physics. However, its device implementation in a single ferroelectric, such as conventional BaTiO3 or PZT ceramics, still presents huge challenges in terms of the poor material conductivity and the energy mismatch between incident photons and ferroelectric switching. Here, using the generation of photocurrent in conductive α‐In2Se3 (a van der Waals ferroelectric) with a two‐terminal planar architecture, the first demonstration of optical‐engineered ferroelectric domain wall in a non‐volatile manner for optoelectronic memory application is reported. The α‐In2Se3 device exhibits a large optical‐writing and electrical‐erasing (on/off) ratio of >104, as well as multilevel current switching upon optical excitation. The narrow direct bandgap of the multilayer α‐In2Se3 ferroelectric endows the device with broadband optical‐writing wavelengths greater than 900 nm. In addition, photonic synapses with approximate linear weight updates for neuromorphic computing are also achieved in the ferroelectric devices. This work represents a breakthrough toward technological applications of ferroelectric nanodomain engineering by light. [ABSTRACT FROM AUTHOR]

Halide perovskite quantum dots (PQDs) are promising materials for diverse applications including displays, light‐emitting diodes, and solar cells due to their intriguing properties such as tunable bandgap, high photoluminescence quantum yield, high absorbance, and narrow emission peaks. Despite the prosperous achievements over the past several years, PQDs face severe challenges in terms of stability under different circumstances. Currently, researchers have overcome part of the stability problem, making PQDs sustainable in water, oxygen, and polar solvents for long‐term use. However, halide PQDs are easily degraded under continuous irradiation, which significantly limits their potential for conventional applications. In this study, an oleic acid/oleylamine (traditional surface ligands)‐free method to fabricate perovskite quantum dot papers (PQDP) is developed by adding cellulose nanocrystals as long‐chain binding ligands that stabilize the PQD structure. As a result, the relative photoluminescence intensity of PQDP remains over ≈90% under continuous ultraviolet (UV, 16 W) irradiation for 2 months, showing negligible photodegradation. This proposed method paves the way for the fabrication of ultrastable PQDs and the future development of related applications. [ABSTRACT FROM AUTHOR]

Realizing solar‐to‐hydrogen (STH) efficiencies close to 20% using low‐cost semiconductors remains a major step toward accomplishing the practical viability of photoelectrochemical (PEC) hydrogen generation technologies. Dual‐absorber tandem cells combining inexpensive semiconductors are a promising strategy to achieve high STH efficiencies at a reasonable cost. Here, a perovskite photovoltaic biased silicon (Si) photoelectrode is demonstrated for highly efficient stand‐alone solar water splitting. A p+nn+ ‐Si/Ti/Pt photocathode is shown to present a remarkable photon‐to‐current efficiency of 14.1% under biased condition and stability over three days under continuous illumination. Upon pairing with a semitransparent mixed perovskite solar cell of an appropriate bandgap with state‐of‐the‐art performance, an unprecedented 17.6% STH efficiency is achieved for self‐driven solar water splitting. Modeling and analysis of the dual‐absorber PEC system reveal that further work into replacing the noble‐metal catalyst materials with earth‐abundant elements and improvement of perovskite fill factor will pave the way for the realization of a low‐cost high‐efficiency PEC system. [ABSTRACT FROM AUTHOR]

Large‐area BiOCl nanosheet arrays grown on Cu substrate are transferred onto the polydimethylsiloxane (PDMS) substrate, while the as‐fabricated BiOCl/PDMS photodetector (PD) yields negligible photocurrents under UV light illumination. The introduction of a Ti3C2Tx MXene conduction layer at the interface increases both the photocurrent and dark current by 2–3 orders of magnitude. But this PD suffers from a large dark current (6.7 pA), a low on–off ratio (2.4), and a long decay time (6.87 s) under 350 nm light illumination at 5 V. After the deposition of ZnO nanoparticles (NPs), the optimized PD achieves a low dark current of 86 fA, a high on–off ratio of 7996.5, and a short decay time of 0.93 s. Additionally, the elimination of the Ti3C2Tx MXene layer causes decreased photocurrent and prolonged decay time. The greatly improved photoresponse and response speed of these PDs are ascribed to the increased light absorption brought by the ZnO NPs, the improved carrier separation promoted by the ZnO–BiOCl heterojunction, and the efficient carrier pathways provided by the Ti3C2Tx MXene conduction layers. The construction of heterojunctions and introduction of conduction additives improve the photodetecting performance of these BiOCl‐based PDs, promoting their practical applications in the photoelectric devices. [ABSTRACT FROM AUTHOR]

Ultraviolet photodetectors (UV PDs) with "5S" (high sensitivity, high signal‐to‐noise ratio, excellent spectrum selectivity, fast speed, and great stability) have been proposed as promising optoelectronics in recent years. To realize high‐performance UV PDs, heterojunctions are created to form a built‐in electrical field for suppressing recombination of photogenerated carriers and promoting collection efficiency. In this progress report, the fundamental components of heterojunctions including UV response semiconductors and other materials functionalized with unique effects are discussed. Then, strategies of building PDs with lattice‐matched heterojunctions, van der Waals heterostructures, and other heterojunctions are summarized. Finally, several applications based on heterojunction/heterostructure UV PDs are discussed, compromising flexible photodetectors, logic gates, and image sensors. This work draws an outline of diverse materials as well as basic assembly methods applied in heterojunction/heterostructure UV PDs, which will help to bring about new possibilities and call for more efforts to unleash the potential of heterojunctions. [ABSTRACT FROM AUTHOR]

Polarizers play a key role in generating polarized light for display, imaging, and data communication, but adoption often suffers from high optical loss. Recently, due to superior optoelectronic properties, halide perovskites have been widely developed for lighting applications; however, highly polarized emission (polarization degree >0.8) has not yet been realized with perovskites. Herein, by incorporating inkjet printing and an anodic aluminum oxide (AAO) confinement strategy, highly ordered perovskite nanowire (NW) arrays are demonstrated for anisotropic optical applications. The optical device based on perovskite NW arrays reveals a high photoluminescence external quantum efficiency of 21.6% and emits highly polarized light with polarization degree up to 0.84. The highly polarized emission from perovskite NW arrays has potential to considerably reduce the optical loss of polarizers, which may attract great interest in developing polarized light sources for next‐generation optoelectronic applications. [ABSTRACT FROM AUTHOR]

Van der Waals (vdW) heterostructures open up excellent prospects in electronic and optoelectronic applications. In this work, mixed‐dimensional metal‐halide perovskite/graphene heterostructures are prepared through selective growth of CH3NH3PbBr3 platelets on patterned single‐layer graphene using chemical vapor deposition. Preferred growth of single‐crystal CH3NH3PbBr3 platelets on graphene surfaces is achieved, which is accompanied by significant photoluminescence quenching. Raman spectra reveal that perovskite platelets cause p‐type doping in the graphene layer. A significant Fermi level decrease of 272 meV in graphene is estimated, which corresponds to a high doping density of 7.5 × 1012 cm−2. Surface potentials measured by Kelvin probe force microscopy indicate a negatively charged perovskite surface under illumination, which is consistent with the upward band bending deduced from conducting atomic force microscopy measurements. Moreover, a field‐effect phototransistor is fabricated using the perovskite/graphene heterostructure channel, and the increased Dirac voltage under illumination confirms an enhanced p‐type character in graphene. These findings enrich the understanding of strong interface coupling in such mixed‐dimensional vdW heterostructures and pave the way toward novel perovskite‐based optoelectronic devices. [ABSTRACT FROM AUTHOR]

Hybrid organic–inorganic materials have been considered as a new candidate in the field of thermoelectric materials since the last decade owing to their great potential to enhance the thermoelectric performance by utilizing the low thermal conductivity of organic materials and the high Seebeck coefficient, and high electrical conductivity of inorganic materials. Herein, we provide an overview of interfacial engineering in the synthesis of various organic–inorganic thermoelectric hybrid materials, along with the dimensional design for tuning their thermoelectric properties. Interfacial effects are examined in terms of nanostructures, physical properties, and chemical doping between the inorganic and organic components. Several key factors which dictate the thermoelectric efficiency and performance of various electronic devices are also discussed, such as the thermal conductivity, electric transportation, electronic band structures, and band convergence of the hybrid materials. [ABSTRACT FROM AUTHOR]

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Semiconductor‐based photodetectors (PDs) convert light signals into electrical signals via the photoelectric effect, which involves the generation, separation, and transportation of the photoinduced charge carriers, as well as the extraction of these charge carriers to external circuits. Because of their specific electronic and optoelectronic properties, metal oxide semiconductors are widely used building blocks in photoelectric devices. However, the compromise between enhancing the photoresponse and reducing the rise/decay times limits the practical applications of PDs based on metal oxide semiconductors. As the behaviors of the charge carriers play important roles in the photoelectric conversion process of these PDs, researchers have proposed several strategies, including modification of light absorption, design of novel PD heterostructures, construction of specific geometries, and adoption of specific electrode configurations to modulate the charge‐carrier behaviors and improve the photoelectric performance of related PDs. This review aims to introduce and summarize the latest researches on enhancing the photoelectric performance of PDs based on metal oxide semiconductors via charge‐carrier engineering, and proposes possible opportunities and directions for the future developments of these PDs in the last section.Charge‐carrier engineering is frequently utilized to break the compromise between enhancing sensitivity and reducing response times in photodetectors based on metal oxide semiconductors. Various strategies aiming to modulate the behaviors of charge carriers and enhance the photoelectric performance are summarized, and possible trends for the future development of these photodetectors are proposed. [ABSTRACT FROM AUTHOR]

Abstract: Researchers have recently revealed that hybrid lead halide perovskites exhibit ferroelectricity, which is often associated with other physical characteristics, such as a large nonlinear optical response. In this work, the nonlinear optical properties of single crystal inorganic–organic hybrid perovskite CH3NH3PbBr3 are studied. By exciting the material with a 1044 nm laser, strong two‐photon absorption‐induced photoluminescence in the green spectral region is observed. Using the transmission open‐aperture Z‐scan technique, the values of the two‐photon absorption coefficient are observed to be 8.5 cm GW−1, which is much higher than that of standard two‐photon absorbing materials that are industrially used in nonlinear optical applications, such as lithium niobate (LiNbO3), LiTaO3, KTiOPO4, and KH2PO4. Such a strong two‐photon absorption effect in CH3NH3PbBr3 can be used to modulate the spectral and spatial profiles of laser pulses, as well as to reduce noise, and can be used to strongly control the intensity of incident light. In this study, the superior optical limiting, pulse reshaping, and stabilization properties of CH3NH3PbBr3 are demonstrated, opening new applications for perovskites in nonlinear optics. [ABSTRACT FROM AUTHOR]

Recent technological advances in conventional planar and microstructured solar cell architectures have significantly boosted the efficiencies of these devices near the corresponding theoretical values. Nanomaterials and nanostructures have promising potential to push the theoretical limits of solar cell efficiency even higher using the intrinsic advantages associated with these materials, including efficient photon management, rapid charge transfer, and short charge collection distances. However, at present the efficiency of nanostructured solar cells remains lower than that of conventional solar devices due to the accompanying losses associated with the employment of nanomaterials. The concurrent design of both optical and electrical components will presumably be an imperative route toward breaking the present-day limit of nanostructured solar cells. This review summarizes the losses in traditional solar cells, and then discusses recent advances in applications of nanotechnology to solar devices from both optical and electrical perspectives. Finally, a rule for nanostructured solar cells by concurrently engineering the optical and electrical design is devised. Following these guidelines should allow for exceeding the theoretical limit of solar cell efficiency soon. [ABSTRACT FROM AUTHOR]

Building on regenerative photoelectrochemical solar cells and emerging electrochemical redox flow batteries (RFBs), more efficient, scalable, compact, and cost-effective hybrid energy conversion and storage devices could be realized. An integrated photoelectrochemical solar energy conversion and electrochemical storage device is developed by integrating regenerative silicon solar cells and 9,10-anthraquinone-2,7-disulfonic acid (AQDS)/1,2-benzoquinone-3,5-disulfonic acid (BQDS) RFBs. The device can be directly charged by solar light without external bias, and discharged like normal RFBs with an energy storage density of 1.15 Wh L−1 and a solar-to-output electricity efficiency (SOEE) of 1.7 % over many cycles. The concept exploits a previously undeveloped design connecting two major energy technologies and promises a general approach for storing solar energy electrochemically with high theoretical storage capacity and efficiency. [ABSTRACT FROM AUTHOR]

In the pursuit of novel functionalities by utilizing the lattice degree of freedom in complex oxide heterostructure, the control mechanism through direct strain manipulation across the interfaces is still under development, especially with various stimuli, such as electric field, magnetic field, light, etc. In this study, the superlattices consisting of colossal-magnetoresistive manganites La0.7Sr0.3MnO3 (LSMO) and photostrictive SrRuO3 (SRO) have been designed to investigate the light-dependent controllability of lattice order in the corresponding functionalities and rich interface physics. Two substrates, SrTiO3 (STO) and LaAlO3 (LAO), have been employed to provide the different strain environments to the superlattice system, in which the LSMO sublayers exhibit different orbital occupations. Subsequently, by introducing light, we can modulate the strain state and orbital preference of LSMO sublayers through light-induced expansion of SRO sublayers, leading to surprisingly opposite changes in photoresistivity. The observed photoresistivity decreases in the superlattice grown on STO substrate while increases in the superlattice grown on LAO substrate under light illumination. This work has presented a model system that demonstrates the manipulation of orbital-lattice coupling and the resultant functionalities in artificial oxide superlattices via light stimulus. [ABSTRACT FROM AUTHOR]

The design and performance of solar cells based on InP grown by the nonepitaxial thin-film vapor-liquid-solid (TF-VLS) growth technique is investigated. The cell structure consists of a Mo back contact, p-InP absorber layer, n-TiO2 electron selective contact, and indium tin oxide transparent top electrode. An ex situ p-doping process for TF-VLS grown InP is introduced. Properties of the cells such as optoelectronic uniformity and electrical behavior of grain boundaries are examined. The power conversion efficiency of first generation cells reaches 12.1% under simulated 1 sun illumination with open-circuit voltage ( VOC) of 692 mV, short-circuit current ( JSC) of 26.9 mA cm−2, and fill factor (FF) of 65%. The FF of the cell is limited by the series resistances in the device, including the top contact, which can be mitigated in the future through device optimization. The highest measured VOC under 1 sun is 692 mV, which approaches the optically implied VOC of ≈795 mV extracted from the luminescence yield of p-InP. [ABSTRACT FROM AUTHOR]