• Acta Photonica Sinica
  • Vol. 51, Issue 2, 0251216 (2022)
FANG Xiangming1, RONG Ping2, REN Shuai2, WANG Zhaoyang2, GAO Shiyong2、*, and WANG Jinzhong2
Author Affiliations
  • 1Department of Materials and Chemical Engineering,Taiyuan University,Taiyuan 030032,China
  • 2School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China
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    DOI: 10.3788/gzxb20225102.0251216 Cite this Article
    Xiangming FANG, Ping RONG, Shuai REN, Zhaoyang WANG, Shiyong GAO, Jinzhong WANG. Preparation and Performance of g-C3N4/Bi2S3 Composite Broad-band Photodetector[J]. Acta Photonica Sinica, 2022, 51(2): 0251216 Copy Citation Text show less

    Abstract

    Broad-band Photodetectors (PDs) become a foucus of current research due to extensive use in missiles guidance, flame monitoring, chemical analysis, biomedical imaging, optical communication and so on. The PDs based on semiconductors, in particular, attach much attention in trerms of their fast response speed, high sensitivity, small volume and weight. Thereinto, the g-C3N4 nanomaterial is proven to possess many benefits for application to PDs such as the unique electronic structure, excellent thermal and chemical properties, non-toxic and raw material sufficient. For further broading the optical detection range and improving the detection performance of the g-C3N4 PD, coupling g-C3N4 and Bi2S3 nanomaterial with a narrow bandgap of 1.3 eV is probably an effective strategy. However, there are few reports on the research of g-C3N4/Bi2S3 composite for PDs. In this study, g-C3N4 and Bi2S3 nanomaterials have been prepared using thermal polymerization method and g-C3N4/Bi2S3 composite structure has been further synthesized with the solution method. The surface morphology of the samples have been characterized through scanning electron microscope. And the results suggest that Bi2S3 particales are attached to g-C3N4 nanosheets, and the layered structure of g-C3N4 is not broken after composited with Bi2S3. The X-ray diffractometer has been used to analyze the crystalline structure of the as-synthesized g-C3N4/Bi2S3 composite. It can be clearly seen that the g-C3N4/Bi2S3 composite has great crystal quality. In addition, the PD based on g-C3N4/Bi2S3 composite structure has been preapred. Under ultraviolet (UV) light illumination, it is indicated that the detection performance of the g-C3N4/Bi2S3 PD for UV light is significantly improved, and its maximum photocurrent is as high as 12.93 μA, which is about 12 times than that of g-C3N4 PD. Meanwhile, the g-C3N4/Bi2S3 PD also exhibits excellent stability and reproductivity, as well as the fast response rise time of 30.36 ms and decay time of 25.56 ms. When exposed to green light at wavelength of 530 nm, the maximum photocurrent of g-C3N4/Bi2S3 PD after 10 times of recycle still remaines steady at about 9.5 μA. Upon irradiation with a red light of wavelength 625 nm, the g-C3N4/Bi2S3 PD also can reach the maximum value (7.6 μA) and then remain stable. Obviously, the g-C3N4/Bi2S3 PD has well photoresponse characteristic and stability compared with the g-C3N4 PD in the visible(Vis) light region, which shows broad-band detection characteristic. What is more, a possible mechanism of UV/Vis detection of the g-C3N4/Bi2S3 PD has been proposed. Apparently, the enhanced detection performance of g-C3N4/Bi2S3 PD is attributed to the formation heterojunction between g-C3N4 and Bi2S3, which refrains the recombination of photogenerated carriers and promotes the efficiency seperation of charges. Besides, the Bi2S3 is a typical narrow bandgap semiconductor, broading the detecton range of g-C3N4/Bi2S3 PD from the UV to Vis region. In view of the excellent performance of the g-C3N4/Bi2S3 composite, the g-C3N4/Bi2S3 is expected to be widely applied in diverse applications, such as photocatalysis, sensors and solar cell, etc.