Solution‐Processed CsPbBr₃ Quantum Dots/Organic Semiconductor Planar Heterojunctions for High‐Performance Photodetectors

Abstract

Planar heterojunctions (PHJs) are fundamental building blocks for construction of semiconductor devices. However, fabricating PHJs with solution-processable semiconductors such as organic semiconductors (OSCs) is a challenge. Herein, utilizing the orthogonal solubility and good wettability between CsPbBr₃ perovskite quantum dots (PQDs) and OSCs, fabrication of solution-processed PQD/OSC PHJs are reported. The phototransistors based on bilayer PQD/PDVT-10 PHJs show responsivity up to 1.64 × 10⁴ A W^-1 , specific detectivity of 3.17 × 10¹² Jones, and photosensitivity of 5.33 × 10⁶ when illuminated by 450 nm light. Such high photodetection performance is attributed to efficient charge dissociation and transport, as well as the photogating effect in the PHJs. Furthermore, the tri-layer PDVT-10/PQD/Y6 PHJs are used to construct photodiodes working in self-powered mode, which exhibit broad range photoresponse from ultraviolet to near-infrared, with responsivity approaching 10^-1 A W^-1 and detectivity over 10⁶ Jones. These results present a convenient and scalable production processes for solution-processed PHJs and show their great potential for optoelectronic applications.