Reinforcement of double built-in electric fields in spiro-MeOTAD/Ga2O3/Si p–i–n structure for a high-sensitivity solar-blind UV photovoltaic detector

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2021-11, Vol.9 (41), p.14788-14798
• Main Authors: Yan, Zuyong, Li, Shan, Yue, Jianying, Ji, Xueqiang, Liu, Zeng, Yang, Yongtao, Li, Peigang, Wu, Zhenping, Guo, Yufeng, Tang, Weihua
• Format: Article
• Language: English
• Subjects: Carrier transport; Electric fields; Gallium oxides; Metalorganic chemical vapor deposition; Optoelectronics; Organic chemicals; Organic chemistry; Photometers; Sensitivity; Spin coating; Ultraviolet radiation
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d1tc03359j

A novel p–i–n self-powered solar-blind UV photodetector based on p-type spiro-MeOTAD (spiro), Ga2O3, and n-type Si is fabricated. The p-type spiro film is spin-coated on the surface of the Ga2O3 film deposited on a Si wafer via a metal–organic chemical vapor deposition (MOCVD) system. Benefitting from the superior carrier-separation ability of the double built-in electric fields, the effective carrier transport of the novel vertical structure and the high solar-blind UV transmittance of the spiro film, the self-powered responsivity of the p–i–n-type photodetector based on spiro/Ga2O3/Si increases to 4.43 mA W−1 under UV light (λ = 254 nm), which is ∼54-fold that of the Ga2O3/Si photodetector (0.22 mA W−1). Meanwhile, the response speed (0.03/0.196 s) of the p–i–n device is also dramatically improved by introducing the spiro layer. The reported achievements of our work provide a new way to construct a high-sensitivity self-powered UV photodetector for photovoltaic and optoelectronic applications.