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Converting non‐visual light into photocurrent while maintaining high visual transparency is vital for semitransparent organic solar cells (ST‐OSCs) application, yet often challenging over insufficient invisible light‐harvesting. Herein, spectrally selective optical manipulation for ST‐OSCs with high visual light transparency and full‐spectral non‐visual light reflection is proposed by matching the optical admittance of ultrathin Ag films using ZnS and MgF2. The reflection of optically enhanced ST‐OSCs at the spectral region beyond the human eye's response spectrum is improved and the transmission in the visual region is simultaneously enhanced. By further integrating an anti‐reflective structure, the optimal structure boosts the average visible transmittance and power conversion efficiency of ST‐OSCs to 44.3% and 12.6%, respectively, yielding a record light utilization efficiency of 5.6%. Corresponding flexible ST‐OSCs with high mechanical stability implies that this work provides a facile and universal strategy for ST‐OSCs aiming at building integrated photovoltaics. [ABSTRACT FROM AUTHOR]

Photodiode‐type solar‐blind photodetectors (SBPDs) with the self‐powered feature hold great promise for applications in unattended secure communication, flame detection, and missile warning. However, the responsivity of SBPDs is usually limited due to the severe solar‐blind (SB) light extinction in substrates and charge transport layers. Herein, a spectrally selective hole extraction structure (SHE) is proposed for high‐efficiency perovskite SBPDs. The SHE consisting of a tandem Fabry–Perot cavity and energy‐level‐matched hole transport layer endows the device with narrowband absorption in the SB region and optimized charge extraction capability from the CsPbI2Br perovskite. The optimized SHE exhibits a peak transmittance of 27% at 255 nm and a half maximum at full width of 28 nm. Under SB light illumination, the champion device achieves a responsivity of 56.20 mA W−1 and a detectivity (D*) of 2.86 × 1013 Jones, which are the record values among the reported results. The approach demonstrated here paves the way for the optical and electrical design of perovskite photodetectors with spectrally selective detection. [ABSTRACT FROM AUTHOR]

The booming growth of all inorganic cesium lead halide perovskites in optoelectronic applications has prompted extensive research interest in the fabrication of ordered nanostructures or microarrays for enhanced device performances. However, the high cost and complexity of commercial lithographic approaches impede the facile fabrication of perovskite microarrays. Herein, CsPbBr3 microarrays with tunable periodicities have been fabricated using a self-assembled polystyrene nanosphere template and a co-evaporation method. The periodicity of CsPbBr3 microarrays is precisely manipulated by simply modifying the size of polystyrene nanospheres. These microarrays are beneficial for light harvesting, leading to better light absorption ability and prolonged photoinduced carrier lifetime. The longest average carrier lifetime of 58.3 ns is obtained for CsPbBr3 microarrays with a periodicity of 1.0 μm. More importantly, the periodic structures of CsPbBr3 microarrays result in a tunable density of emitter tips in field emission devices. Compared to compact CsPbBr3 films, a 68.2% decrease of the turn-on field is observed for CsPbBr3 microarrays when the periodicity is 150 nm. The higher density of emitter tips leads to larger local field enhancement, and hence the largest field enhancement factor of 3346.6. Finally, a good emission current stability for CsPbBr3 microarray-based field emission devices has been demonstrated. [ABSTRACT FROM AUTHOR]

2D materials have been extensively applied in electronic and optoelectronic devices due to their unique and extraordinary electrical and optical properties. Among them, tin disulfide (SnS2) has attracted enormous research interests due to its low‐cost, earth‐abundant, environment friendly properties as well as superior performance in photodetectors. Here, an outstanding in‐plane SnS2 phototransistor with an out‐of‐plane built‐in electric field enabled by molybdenum oxide (MoO3) surface functionalization is demonstrated. The photocarriers are generated and effectively separated by the vertical electric field, leading to a high photoresponsivity of 2.3 × 103 A⋅W−1, photoconductive gain of >105, external quantum efficiency exceeding 8%. It also demonstrates a low noise power density, revealing an ultrasensitive photodetection with specific detectivity up to 3.2 × 1012 Jones. The formation of the out‐of‐plane built‐in electric field is validated by the output electrical transport measurement of SnS2 vertical transistor, and further corroborated by in situ ultraviolet photoelectron spectroscopy and X‐ray photoelectron spectroscopy characterizations. The findings promise surface functionalization as an effective approach to induce an internal electric field in 2D multilayer SnS2 towards its application in high performance photodetection. [ABSTRACT FROM AUTHOR]

ZnO has broad applications in optoelectronic devices, including ultraviolet light emitters and photodetectors. Herein we report the impact of MoO3 surface functionalization on the photoresponse of epitaxially grown ZnO. Under illumination with 350 nm UV light, the photocurrent of ZnO is found to be enhanced by 2.87 times after the deposition of 0.2 nm MoO3. As corroborated by in situ ultraviolet photoelectron spectroscopy and X-ray photoelectron spectroscopy results, the enhanced photoresponse derives from MoO3 related gap states within the band gap of ZnO and larger upward band bending at the interface, which is attributed to the strong electron transfer from ZnO to MoO3. Moreover, photoluminescence results reveal that the recombination probability of the photo-generated charge carriers in ZnO is reduced after MoO3 surface functionalization. [ABSTRACT FROM AUTHOR]

Using scanning tunneling microscopy (STM) together with density functional theory (DFT) the growth behavior of perylene on the Cu(100) substrate has been investigated. As revealed by STM images, perylene molecules prefer to adopt lying configuration with their molecular plane parallel to the substrate, and two symmetrically equivalent ordered domains were observed. DFT calculations show that perylene molecule prefers to adsorb on the top site of substrate Cu atoms with its long molecular axis aligning along the [011] or [01-1] azimuth of the substrate which is the most stable adsorption geometry according to its highest binding energy. Consequently, two adsorption structures of c(8×4) and c(8×6), each containing two perylene molecules per unit cell, are proposed based on our STM images. The growth mechanism for ordered perylene domains on Cu(100) can be attributed to the balance between weak adsorbate-adsorbate interaction and comparable adsorbate-substrate interaction. [ABSTRACT FROM AUTHOR]

Growth of ordered perylene thin films on the Ag(110) surface has been investigated with scanning tunneling microscope. By saturating the surface with a monolayer of perylene molecules, two kinds of ordered structures are simultaneously formed with flat-lying perylene molecules on the Ag(110) surface, in which one is commensurate relative to the Ag substrate with a periodicity of (Multiple line equation(s) cannot be represented in ASCII text) while the other is commensurate with a periodicity of (Multiple line equation(s) cannot be represented in ASCII text). There is one molecule within the former unit cell with a surface coverage of 0.1 molecule per Ag atom, while there are two molecules within the latter unit cell, which gives a slightly lower surface coverage of 0.091 molecule per Ag atom. Ab initio calculations have been carried out to identify the adsorption geometry and bonding sites. [ABSTRACT FROM AUTHOR]