Silver-ion-passivated black phosphorus photodetectors to improve the response time

• Published in: New journal of chemistry 2023-04, Vol.47 (15), p.7432-7437
• Main Authors: Zuo, Huilin, Bai, Jing, Wang, Chenglin, Ni, Junhao, Ding, Yang, Pan, Bingyu, Cai, Zhengyang, Xiao, Shaoqing, Gu, Xiaofeng, Zhang, Xiumei, Nan, Haiyan
• Format: Article
• Language: English
• Subjects: Correlation coefficients; Flakes (defects); Oxidation; Phosphorus; Photoelectric effect; Photoelectrons; Photometers; Silver nitrate; X ray photoelectron spectroscopy
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d3nj00470h

We present a remarkable improvement in the photoresponse time of few-layer black phosphorus (BP) following treatment with silver nitrate solution, with the rise time being reduced from 1.71 s to 50 ms and the fall time being reduced from 3.25 s to 80 ms. X-ray photoelectron spectroscopy (XPS) was utilized to analyze the surface of the treated BP flakes, and the role of Ag + in diminishing the surface activity of BP devices was evaluated. Moreover, the adsorption of Ag + was observed to effectively hinder the oxidation of the BP surface, resulting in a decrease of the hysteresis from 85.6 V to 29 V. By analyzing the correlation coefficients of photocurrent and laser power, we suggest that the improved performance of the photodetector is caused by the presence of BP(Ag + ) on the surface, which significantly decreases the concentration of defects in BP and thus the concentration of trap states. Black phosphorus following treatment with silver nitrate solution shows a remarkable improvement in the photoresponse time because Ag + adsorption helps to reduce the defect concentration in it.