High-Performance Self-Driven Single GaN-Based p–i–n Homojunction One-Dimensional Microwire Ultraviolet Photodetectors
Guohui Wu, Linyuan Du, Congcong Deng, Fei Chen, Shaobin Zhan, Qing Liu, Can Zou, Zixuan Zhao, Kai Chen, Fangliang Gao, Shuti Li
Abstract
With the increasing global concern about energy consumption, self-driven photodetectors are especially attractive. In this paper, we prepared high-performance self-driven single GaN-based p–i–n homojunction one-dimensional microwire ultraviolet photodetectors (UV PDs) with a vertical structure. High-quality trapezoidal GaN-based p–i–n homojunction microwires were selectively heteroepitaxially grown on a patterned Si(100) substrate by metal organic chemical vapor deposition (MOCVD). The upper and lower electrodes were separated by simple spin-coating and photolithography. The single GaN-based p–i–n homojunction microwire UV PDs show outstanding self-driven performance under 325 nm light irradiation, including a low dark current (10 pA), a fast response speed (Tr = 1.12 ms/Td = 2.8 ms), and an excellent detectivity (1.30 × 1012 jones). In addition, the UV PDs have a high responsivity (251 mA/W) at 0 V. The high performance of the UV PDs is mainly due to the wider built-in electric field formed in the p–i–n junction and vertical conductive structure with reduced dimensionality. This study not only provides a simple and feasible method to fabricate one-dimensional vertical-structured microwire UV PDs but also provides a basis for the subsequent fabrication of UV PDs with high-performance self-driven homojunctions.