Ultra-High Performance Broadband Self-Powered Photodetector Based on Modified Sb₂Se₃/ZnO Heterojunction

Ascribing to the low power consumption, self-powered photodetectors (SPPDs) have promising applications in optical communication and photoelectric imaging. Aiming to improve the performance of SPPDs, many efforts have been devoted to exploring the semiconductor-heterojunction candidates. However, key parameters of SPPDs, especially the responsivity and response time, still lag behind those of the standard photodetectors. Here, with the modification of the transport behavior, ultra-high-performance SPPDs are fabricated based on the reported Sb₂Se₃/ZnO heterojunction. Keeping the broadband detection from infrared to UV region, the SPPDs achieve increased responsivity and detectivity of 0.38 A W⁻¹ and 1.40 × 10¹³ Jones, respectively. Especially, according to the cut-off frequency measurements, the response time is improved to 93.5/75.0 ns, which is in a microsecond, even millisecond level for most of the current SPPDs. These studies further reveal the mechanism of the performance modification and indicate that this method can be applied to fabricate imaging arrays. With the combination of the experimental results, we provide an effective method for enhancing the performance of SPPDs toward their applications.