Solution‐Processed CsPbBr(3) Quantum Dots/Organic Semiconductor Planar Heterojunctions for High‐Performance Photodetectors

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 CsPbBr(3) 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 × 10(4) A W(−1), specific detectivity of 3.17 × 10(12) Jones, and photosensitivity of 5.33 × 10(6) 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 10(6) Jones. These results present a convenient and scalable production processes for solution‐processed PHJs and show their great potential for optoelectronic applications.