Improved detection performance of self-driven InZnO / p-GaN heterojunction UV photodetector by lanthanum doping

• Published in: Journal of alloys and compounds 2023-12, Vol.966, p.171537, Article 171537
• Main Authors: Ding, Haoran, Peng, Yi, Chen, Meiqin, Yufei, Yang, Wang, Nan, Hu, Xuhong, Deng, Jianyu, Sun, Wenhong
• Format: Article
• Language: English
• Subjects: IZO / GaN heterostructure; Lanthanum doping; Sol-gel method; Ultraviolet photodetector
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2023.171537

By using the sol-gel spin-coating method, La-InZnO films with different La (0 at%, 2 at%, 4 at%, and 6 at%) doping concentrations were grown on p-GaN / sapphire film templates, and self-driven p-GaN / n-ZnO heterojunction ultraviolet (UV) detectors were prepared. The effects of La doping concentration on the microstructure, optical, and electrical properties of synthesized La-InZnO films were studied. In addition, the optical sensing characteristics and photoelectric response performance of four p-n heterojunction UV detectors were compared. La doping can decrease the content of oxygen vacancies. It also reduces the carrier concentration and mobility of the films. At zero bias voltage, the 2 at% doped device has the best performance, with a peak responsivity of 46 mA/W at 366 nm, a high spectral selectivity full width at half maximum (FWHM) of only 6.92 nm, and a fast response with the rise and decay times of 1.15 ms and 2.42 ms, respectively. This study demonstrates a feasible method for improving the performance of self-driven heterojunction UV detectors. •Simple and easy to prepare large area by sol-gel method.•n-ZnO/p-GaN heterojunction detector can operate without external power supply.•Lanthanide doping can improve detector responsiveness and spectral selectivity, and reduce response time.•2 at% of lanthanum doping is the optimal doping concentration.