Ultrathin CuBi2O4 on a bipolar Bi2O3 nano-scaffold: a self-powered broadband photoelectrochemical photodetector with improved responsivity and response speed. Issue 13 (14th March 2023)

• Record Type: Journal Article
• Authors: Dong, Boheng; Zhang, Xinya; Cheng, Hui; Jiang, Xiang; Wang, Fuxian
• Is Part Of: Nanoscale. Volume 15:Issue 13(2023)
• Page Start: 6333
• Page End: 6342
• Publication Date: 2023-03-14
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/d3nr00118k
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Bi2 O3 nano-scaffold supported ultrathin CuBi2 O4 exhibits improved light absorption and charge separation, enabling self-powered photodetection of broadband light with high responsivity (75 mA W −1 ) and response speed (0.18/0.19 ms). Abstract : CuBi2 O4 is a promising photoactive material for photoelectrochemical (PEC) broadband photodetectors due to its suitable band structure, but its photo-responsivity is severely limited by the short carrier diffusion length and long light penetration depth. To address the trade-off between light absorption and charge separation, a nano-structured bipolar Bi2 O3 host scaffold was coupled with an ultrathin CuBi2 O4 light absorbing layer to construct a host–guest Bi2 O3 /CuBi2 O4 photocathode. The work function of the bipolar Bi2 O3 scaffold lies in between FTO and CuBi2 O4, making Bi2 O3 a suitable back contact layer for hole transport. Compared with the flat CuBi2 O4 and Bi2 O3 scaffold counterpart, the nanostructured Bi2 O3 /CuBi2 O4 exhibits significantly improved light absorption and enhanced charge separation efficiency. The Bi2 O3 /CuBi2 O4 PEC photodetector can be self-powered and demonstrates a broad photo-response ranging from ultraviolet (UV) to near infrared (NIR). It shows a high responsivity of 75 mA W −1 and a remarkable short response time of 0.18 ms/0.19 ms. Bi2 O3 /CuBi2 O4 prepared by magnetron sputtering demonstrates great potential for rapid PEC photodetection in a wide optical domain.