Carrier recombination suppression and transport enhancement enable high‐performance self‐powered broadband Sb2Se3 photodetectors

• Published in: InfoMat 2023-04, Vol.5 (4), p.n/a
• Main Authors: Chen, Shuo, Fu, Yi, Ishaq, Muhammad, Li, Chuanhao, Ren, Donglou, Su, Zhenghua, Qiao, Xvsheng, Fan, Ping, Liang, Guangxing, Tang, Jiang
• Format: Article
• Language: English
• Subjects: Aluminum; Antimony compounds; Broadband; Buffer layers; Carrier recombination; Carrier transport; Electromagnetic absorption; Graphene; Heterojunctions; Lasers; Light; Nanowires; Optoelectronics; Photometers; photoresponse; Photovoltaic cells; recombination suppression; Sb2Se3; Selenides; Self-assembly; self‐powered photodetector; Signal to noise ratio; Thin films; transport enhancement
• ISSN: 2567-3165; 2567-3165
• DOI: 10.1002/inf2.12400

Antimony selenide (Sb2Se3) is a promising candidate for photodetector applications boasting unique material benefits and remarkable optoelectronic properties. Achieving high‐performance self‐powered Sb2Se3 photodetector through a synergistic regulation of absorber layer and heterojunction interface demonstrates great potential and needs essential investigation. In this study, an effective two‐step thermodynamic/kinetic deposition technique containing sputtered and selenized Sb precursor is implemented to induce self‐assembled growth of Sb2Se3 light absorbing thin film with large crystal grains and desirable [hk1] orientation, presenting considerable thin‐film photodetector performance. Furthermore, aluminum (Al3+) cation dopant is introduced to modify the optoelectronic properties of CdS buffer layer, and further optimize the Sb2Se3/CdS (Al) heterojunction interface quality. Thanks to the suppressed carrier recombination and enhanced carrier transport kinetics, the champion Mo/Sb2Se3/CdS (Al)/ITO/Ag photodetector exhibits self‐powered and broadband characteristics, accompanied by simultaneously high responsivity of 0.9 A W−1 (at 11 nW cm−2), linear dynamic range of 120 dB, impressive ON/OFF switching ratio over 106 and signal‐to‐noise ratio of 109, record total noise determined realistic detectivity of 4.78 × 1012 Jones, and ultra‐fast response speed with rise/decay time of 24/75 ns, representing the top level for Sb2Se3‐based photodetectors. This intriguing work opens up an avenue for its self‐powered broadband photodetector applications. The thermodynamic/kinetic controlled self‐assembled growth of high‐quality Sb2Se3, accompanied with Al3+ cation doping in CdS induced heterojunction interface optimization can remarkably suppress carrier recombination and enhance carrier transport. Consequently, the champion Sb2Se3/CdS (Al) photodetector exhibits self‐powered broadband characteristics, accompanied by simultaneously high responsivity (0.9 A W−1), record detectivity (4.78 × 1012 Jones), and ultra‐fast response speed (rise/decay time of 24/75 ns).