Large-area hierarchical Bi2O2S flowers composed of 2D ultrathin nanosheets for high performance self-powered IR photodetector

Currently, bismuth oxychalcogenide family (Bi 2 O 2 X, X=S, Se, Te), led by Bi 2 O 2 Se with unique characteristics, have emerged as promising candidates for high-performance optoelectronic devices. Herein, the novel Bi 2 O 2 S flowers with hierarchical structure have been successfully prepared via a facile hydrothermal method with only 3 h of reaction. The as-prepared Bi 2 O 2 S flower is composed of many ultrathin nanosheets (NSs) with a thickness of about 12-16 nm. And the possible formation mechanism of ultrathin NSs self-assembled Bi 2 O 2 S flowers was further analyzed. In addition, a self-powered infrared photodetector based on Bi 2 O 2 S flowers, which can work without an external power, is designed. Under illumination at 850 nm light, the Bi 2 O 2 S flowers photodetector exhibits well photoresponse switching behaviors, of which the high responsivity, detectivity and fast response time reach up to 9.48 mA/W, 9.96×10 10 Jones and 27.83 ms, respectively. Of particular note, the Bi 2 O 2 S flowers photodetector also possesses the eximious stability. ● Large-area hierarchical Bi 2 O 2 S flowers composed of 2D ultrathin nanosheets were successfully prepared on the fluorine-doped tin oxide substrate. ● The Bi 2 O 2 S flowers infrared photodetector exhibits well photoresponse switching behaviors, of which the high responsivity, detectivity and fast response time reach up to 9.48 mA/W, 9.96×10 10 Jones and 27.83 ms, respectively. ● The Bi 2 O 2 S flowers infrared photodetector possesses the eximious stability, and can operated without an external power source.