UV and NIR Dual-Band Photodetector Enabled by p-Type Perovskite and Semitransparent Microcavity
Qingshan Fan, Keqiang Li, Hanqing Zhang, Chenyang Han, Zhanzheng Wang, Qiong Li, Zunmin Wan, Yu Zhou, Xiaodong Liu, Jiang Huang
Abstract
Narrowband photodetectors (NPDs) are essential for surveillance, photometry, and remote sensing. However, few studies have demonstrated multiple narrowband detection abilities within a single PD, particularly in the ultraviolet (UV) and near-infrared (NIR) regions, which are not directly recognized by the human eyes. In this work, we present a method for UV and NIR dual-band photodetection on the same device through integrating tandem-like perovskite/organic bulk-heterojunction (P-OBHJ) with a translucent microcavity. By leveraging the self-doping effect of perovskites, we fabricated p-type MAPbI 3 films with the unbalanced electron–hole transport, enabling complete visible-light depletion upon bottom illumination. Meanwhile, NIR light passes through the entire perovskite layer to reach the OBHJ layers, ultimately resulting in a narrowband response to NIR light. Upon top illumination, the semitransparent microcavity selectively transmits only UV light, achieving narrowband UV detection. As a result, the optimized device exhibits the responsivity of 0.21 and 0.03 A/W with the corresponding shot-noise-limited specific detectivity reaching 4 × 10 12 and 6 × 10 11 Jones, at the peak wavelengths of 810 and 330 nm, respectively. Last, we showcase prototype applications of the dual-band PDs as heartbeat and solar UV intensity monitors, providing a novel strategy for the development of multifunctional NPD.