Copper-based halide perovskites have shown great potential in lighting and photodetection due to their excellent photoelectric properties, good stability and lead-free nature. However, as an important piece of copper-based perovskites, the synthesis and application of RbCu2I3 have never been reported. Here, we demonstrate the synthesis of high-quality RbCu2I3 microwires (MWs) by a fast-cooling hot saturated solution method. The prepared MWs exhibit an orthorhombic structure with a smooth surface. Optical measurements show the RbCu2I3 MWs have a sharp ultraviolet absorption edge with 3.63 eV optical band gap and ultra-large stokes shift (300 nm) in photoluminescence. The subsequent photodetector based on a single RbCu2I3 MW shows excellent ultraviolet detection performance. Under the 340 nm illumination, the device shows a specific detectivity of 5.0 × 109 Jones and a responsivity of 380 mA·W−1. The synthesis method and physical properties of RbCu2I3 could be a guide to the future optoelectronic application of the new material.
Youchao Kong,Pinsen Zhang,Donghua Fan,Xiaoshuang Li,Shanshan Yan
Assembling perovskites into heterojunctions enables multifunctional high-performance photodetectors. Compared with vertical heterojunctions, lateral heterojunctions enhance the optoelectronic performance of devices due to the direct contact between the photosensitive layer and light, reducing light reflection losses. However, the fabrication of all-perovskite lateral heterojunctions is challenging through a solution method. The first perovskites formed are easily dissolved by the solvent of the second precursor, hindering their further application in photodetectors. In this study, we have developed a preparation process for the lateral microwire (MW)/film heterojunction and the Ag/RbCu2I3 MW/MAPbBr3 film/indium tin oxide heterojunction photodetector by utilizing an optical fiber-based physical transfer step. Thanks to the high-quality RbCu2I3 MW/MAPbBr3 film lateral heterojunction, the device demonstrated excellent optoelectronic performance at 0 V bias voltage, with a responsivity of 0.79 mA·W–1 and a detectivity of 5.34 × 1012 Jones under 339 nm radiation. In addition, the device exhibited consistent and rapid response times under 355 and 450 nm irradiation. This optical fiber-based physical transfer method provides a self-powered light detection strategy for the preparation of all-perovskite lateral heterojunctions.
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