Self‐Powered FAPbI ₃ Perovskite Quantum Dot Photodetector With Fast Response and Wide Linear Dynamic Range

Perovskite quantum dots (PQD) are emerging as promising materials for photodetector technology due to their exceptional optical and electrical properties and ease of solution processability. However, their practical deployability is hindered by their limited linear photocurrent response and slow response speed needed for real‐world applications. In this work, we investigate formamidinium lead triiodide (FAPbI 3 ) PQD‐based photodetectors, focusing on enhancing their performance for practical applications. The ligand‐functionalized FAPbI 3 PQD‐based photodetector showcased excellent performance with a remarkable linear dynamic range (LDR) of 181 dB and a fast response speed of 260 ns. The device exhibits excellent responsivity of 377 mA W −1 and specific detectivity of 2.9 × 10 12 Jones due to uniform and compact film morphology and improved carrier transport. In addition, a −3 dB cut‐off frequency of 128 kHz is achieved, primarily limited by the slow‐decaying tail of the TPC signal. This study demonstrates meaningful progress in perovskite QD photodetector technology, reinforcing their promise for next‐generation optoelectronic systems.