Pyro-Phototronic Effect enhanced position-sensitive detection observed in ZnO nanowires/Ag2S quantum dots heterojunction

Abstract

The development of position-sensitive detectors (PSDs) with high sensitivity and ultrafast response is essential for advanced applications like dynamic tracking and artificial vision. However, limited light absorption and inefficient carrier separation are two major factors constraining the performance of PSDs. Here, we use a pyro-phototronic coupling strategy to address these challenges and develop a high-sensitivity, ultrafast, broadband PSD based on ZnO nanowires/Ag2S quantum dots heterojunction. The pyro-phototronic effect provides an enhanced electric field to facilitate carrier separation and transport, and thus the photoresponse enhancement factor of the heterojunction PSD reached 332.4%. Correspondingly, the heterojunction PSD exhibits a high sensitivity of 230.6 mV/mm, an ultrafast response time of 9.4 μs, and a broad detection range from 405 to 980 nm. We propose a pyroelectric-field-driven carrier diffusion model to elucidate the underlying physical mechanism for the performance enhancement. This work not only provides a useful strategy for developing high-sensitivity, fast-response optoelectronic devices but also holds significant potential for applications in dynamic tracking and real-time sensing technologies.