Quantum-dot ZnO–CsPbBr3 interlayer induced high-performance ZnO nanoarray/CsPbBr3 photodetector†

Recent advances in halide perovskite quantum dot (QD) photodetector based ZnO nanoarrays (ZnO NRs) have been constrained by significant non-radiative recombination losses at quantum dot interfaces. To address this challenge, an innovative device architecture combined with a tailored quantum dot (QD) CsPbBr₃–ZnO composite (P-ZnO) interlayer was designed. The vertically oriented ZnO nanoarrays function as high-mobility electron highways, while the optimized P-ZnO interlayer simultaneously enhances photon harvesting and minimizes interfacial recombination losses. The photodetector incorporating the optimized P-ZnO interlayer demonstrates exceptional performance characteristics, achieving a current modulation ratio exceeding 10³, a photoresponsivity of 99.73 mA W⁻¹, and a specific detectivity of 6.08 × 10¹¹ Jones under 450 nm illumination. Also, the P-ZnO nanocomposite layer enables a remarkable suppression of dark current to 0.423 nA while simultaneously boosting photocurrent generation to 1.166 μA. This work establishes a facile and scalable fabrication approach for engineering high-efficiency perovskite quantum dot photodetectors.