Synthesis of Thin Bi 9 O 7.5 S 6 Nanosheets for Improved Photodetection in a Wide Wavelength Range

• Published in: Chemistry, an Asian journal an Asian journal, 2021-11, Vol.16 (22), p.3748-3753
• Main Authors: Yi, Ronghua, Wang, Jin, Yue, Xiaoping, Liang, Yan, Li, Zhuoyao, Sheng, Huixiang, Guan, Mengdan, Zhu, Yameng, Sun, Qizeng, Wang, Li, Huang, Xiao, Lu, Gang
• Format: Article
• Language: English
• ISSN: 1861-4728; 1861-471X
• DOI: 10.1002/asia.202100963

Bismuth‐based compounds possess layered structures with a variety of stacking modes, endowing the compounds with diverse properties. As one type of bismuth oxysulfides, Bi 9 O 7.5 S 6 nanocrystals has great applications in photodetection; however, the responsivity of bulky Bi 9 O 7.5 S 6 is limited due to the poor charge separation. Herein, single‐crystalline Bi 9 O 7.5 S 6 thin nanosheets are successfully synthesized by using a solvothermal method. The thickness of the obtained Bi 9 O 7.5 S 6 nanosheets is down to 15 nm and can be easily tuned by varying the reaction period. Moreover, the Bi 9 O 7.5 S 6 nanosheets show strong light absorption in the visible and near infrared range, making it a promising candidate in optoelectronics. As a demonstration, the thin Bi 9 O 7.5 S 6 nanosheets are used as active layer in an optoelectronic device, which exhibits sensitive photoelectric response to light in a wide range of 400–800 nm. The responsivity of the device reaches up to 1140 μA W −1 , and the performance of the device is stable after long‐period illumination. This work demonstrates a great potential of the thin Bi 9 O 7.5 S 6 nanosheets in optoelectronic devices, and these nanosheets may also be extended to various optoelectronic applications.