Mixed-dimensional CsPbBr3@ZnO heterostructures for high-performance p-n diodes and photodetectors

Abstract

Mixed one-dimensional (1D) and three-dimensional (3D) heterostructures, with synergistic advantages of different dimensionalities, have shown unique optical properties due to their large junction areas and high absorption cross-sections, which may also bring superior electrical and optoelectronic performances. However, due to the challenge in designing and constructing a proper 1D-3D p-n junction, their electronic properties and potential application are still unclear. Here, a type of 1D-3D ZnO/CsPbBr3 p-n junction is constructed by liquid-phase growth of crystalline CsPbBr3 microplates on ZnO nanowires, which exhibit excellent properties of p-n diode and serve as high-performance rectifier and photodetector. As a rectifier, it shows characteristics of ambipolar transfer and its rectification ratio reaches up to 106. As a photodetector, it covers light from ultraviolet to visible light. High photoelectric switching ratio (107), responsivity (3.5 × 103 A/W), detectivity (6.6 × 1013 Jones) and external quantum efficiency (1.7 × 106%) are obtained under 254 nm light illumination. Meanwhile, the switching ratio, responsivity, detectivity and external quantum efficiency are 103, 41.5 A/W, 4.96 × 1012 Jones and 1.086 × 103%, respectively, under 473 nm laser illumination. The decay length of photo-generated carriers in ZnO/CsPbBr3 heterojunction is demonstrated longer than that in original CsPbBr3 crystal, which is further controlled by adjusting the potential barriers between the CsPbBr3 and ZnO with a tunable external electric field.