High-performance omnidirectional self-powered photodetector constructed by CsSnBr_(3)/ITO heterostructure film

Omnidirectional photodetectors attract enormous attention due to their prominent roles in optical tracking systems and omnidirectional cameras.However,it is still a challenge for the construction of high-performance omnidirectional photodetectors where the incident light can be effectively absorbed in multiple directions and the photo-generated carriers can be effectively collected.Here,a high-performance omnidirectional self-powered photodetector based on the CsSnBr_(3)/indium tin oxide(ITO)heterostructure film was designed and demonstrated.The as-fabricated photodetector exhibited an excellent self-powered photodetection performance,showing responsivity and detectivity up to 35.1 mA/W and 1.82×10^(10) Jones,respectively,along with the smart rise/decay response time of 4 ms/9 ms.Benefitting from the excellent photoelectric properties of the CsSnBr_(3) film as well as the ability of the CsSnBr_(3)/ITO heterostructure to efficiently separate and collect photo-generated carriers,the as-fabricated photodetector also exhibited an excellent omnidirectional self-powered photodetection performance.All the results have certified that this work finds an efficient way to realize high-performance omnidirectional self-powered photodetectors.

Recent advances in Ga-based solar-blind photodetectors

Solar-blind ultraviolet photodetectors have many advantages, such as low false alarm rates, the ability to detect weak signals, and high signal-to-noise ratios. Among the various functional solar-blind ultraviolet photodetectors, Ga-based alloys of AlGaN and Ga_2O_3 are the most commonly adopted channel semiconductor materials and have attracted extensive research attention in the past decades. This review presents an overview of the recent progress in Ga-based solar-blind photodetectors. In case of AlGaN-based solar-blind ultraviolet photodetectors, the response properties can be improved by optimizing the AlN nucleation layer and designing the avalanche structure. On the other hand, we also discuss the morphology and growth methods of Ga_2O_3 nanomaterials and their effect on the performance of the corresponding solarblind photodetectors. The mechanically exfoliated Ga_2O_3 flakes show good potential for ultraviolet detection. Also, Ga_2O_3 nanoflowers and nanowires reveal perfect response to ultraviolet light. Finally, the challenges and future development of Ga-based functional solar-blind ultraviolet photodetectors are summarized.

Stoichiometric effect on electrical and near-infrared photodetection properties of full-composition-range GaAs1−xSbx nanowires

As one of the most important narrow bandgap ternary semiconductors, GaAs1−xSbx nanowires (NWs) have attracted extensive attention recently, due to the superior hole mobility and the tunable bandgap, which covers the whole near-infrared (NIR) region, for technological applications in next-generation high-performance electronics and NIR photodetection. However, it is still a challenge to the synthesis of high-quality GaAs1−xSbx NWs across the entire range of composition, resulting in the lack of correlation investigation among stoichiometry, microstructure, electronics, and NIR photodetection. Here, we demonstrate the success growth of high-quality GaAs1−xSbx NWs with full composition range by adopting a simple and low-cost surfactant-assisted solid source chemical vapor deposition method. All of the as-prepared NWs are uniform, smooth, and straight, without any phase segregation in all stoichiometric compositions. The lattice constants of each NW composition have been well correlated with the chemical stoichiometry and confirmed by high-resolution transmission electron microscopy, X-ray diffraction, and Raman spectrum. Moreover, with the increase of Sb concentration, the hole mobility of the as-fabricated field-effect-transistors and the responsivity and detectivity of the as-fabricated NIR photodetectors increase accordingly. All the results suggest a careful stoichiometric design is required for achieving optimal NW device performances.

Thickness-dependent highly sensitive photodetection behavior of lead-free all-inorganic CsSnBr_(3) nanoplates

Non-layered two-dimensional(2D) lead-free all-inorganic perovskites nanoplates have recently attracted considerable attention in photodetectors;however, the indepth investigation of thickness on photodetection performance is still lacking. In this work, by constructing the famous metal-semiconductor-metal photodetectors, the photodetection behaviors of thickness-controlled CsSnBr;nanoplates are investigated systematically. Ni electrodes are adopted for ensuring the good ohmic contact behaviors of as-fabricated photodetectors. With the increase in thickness, the photodetection performances improve accordingly, such as photocurrent increases from 0.22 to 19.40 nA, responsivity increases from 72.9 to 4893.7 mA·W^(-1), rise/decay time decreases from 11/35 to 3/10 ms, respectively. Notability, the dark current also increases with the increase in thickness, making the further investigation on the reduction in dark current meaningful.All of the as-fabricated photodetectors are stable, suggesting the careful thickness selection in next-generation high-performance lead-free all-inorganic perovskites photodetectors.