High-performance phototransistors based on heterojunctions of organic semiconductors and 2D perovskite single crystals

Two-dimensional (2D) organic–inorganic hybrid perovskites are promising candidates for optoelectronic applications owing to their excellent optoelectronic properties and enhanced stability compared to their three-dimensional counterparts. However, the optoelectronic performance of 2D perovskite single crystals is often constrained by low charge transport efficiency. Herein, we fabricated a (PEA)2PbI4/PDVT-10 heterojunction and corresponding phototransistor by transferring a mechanically exfoliated (PEA)2PbI4 single crystal onto a PDVT-10 film. This design strategically combines the exceptional light-harvesting ability of the perovskite with the high charge carrier mobility and gate tunability of the organic semiconductor. As a result, the concerted action of the photoconductive and field effects within the heterojunction yields outstanding photodetection metrics. Compared to the PDVT-10 device, the (PEA)2PbI4/PDVT-10 device shows a twofold improvement in photosensitivity (Ilight/Idark ∼ 1.1 × 103 @ 64 mW cm−2), a nearly three-order-of-magnitude increase in photocurrent, and a 32-fold higher responsivity (0.65 A W−1, @ 0.01 mW cm−2). This study provides a viable strategy for integrating the superior properties of perovskite single crystals and organic semiconductors to fabricate high-performance photodetectors.