High-performance layer-structured Si/Ga2O3/CH3NH3PbI3 heterojunction photodetector based on a Ga2O3 buffer interlayer

• Published in: Applied optics (2004) 2023-02, Vol.62 (6), p.A76
• Main Authors: Wang, Guibao, Pang, Tiqiang, Sun, Kai, Luan, Suzhen, Zhang, Yuming, Yuan, Lei, Jia, Renxu
• Format: Article
• Language: English
• Subjects: Absorptivity; Buffer layers; Density; Electron tunneling; Energy levels; Film thickness; Gallium oxides; Heterojunctions; Holes (electron deficiencies); Hybrid structures; Interlayers; Metal halides; Optoelectronic devices; Perovskites; Photometers; Silicon; Silicon wafers; Thin films
• ISSN: 1559-128X; 2155-3165
• DOI: 10.1364/AO.472922

Organic–inorganic metal halide perovskite-based photodetectors (PDs) have attracted great attention because they exhibit extraordinary optoelectronic performances due to advantages such as a low trap-state density and large absorption coefficient. As a buffer layer, Ga2O3 can block electron hole recombination, passivate an Si surface, reduce trap density, and improve the ability of electron tunneling. Here, we demonstrate a trilayer hybrid structure (Si/Ga2O3/CH3NH3PbI3) composed of an n-type silicon wafer, Ga2O3 interlayer, and CH3NH3PbI3 thin film. The effect of different Ga2O3 layer thicknesses on the characteristics of a PD was studied, which shows that the responsivity first increases and then decreases with an increase in the Ga2O3 film thickness; the optimized Ga2O3 thickness is 300 nm. Additionally, the optimal responsivity, detectivity, and the rise and decay times are 7.2mAW-1, 7.448x1010 Jones, and 39 and 1.7 ms, respectively. This device has a better performance because Ga2O3 and perovskite have a matched energy level. We believe our work could provide a new way to fabricate high-performance optoelectronic devices.