Low-Temperature Growth of High-Quality Ag2HgS2 Crystals for Setup of Weak-Light UV-Visible-NIR Photodetectors

Weak-light photodetection shows considerable potential in both theoretical and technical aspects while it would be a key issue to explore new candidate materials for practical application in view of high reliability and durability of the devices under ambient conditions. In this work, Ag2HgS2 single crystal rods (SCRs) with length up to 1.2 cm and width ranging from 10 to 200 mu m are successfully fabricated in pure phase via facile solvothermal process at 200 degrees C for 24 h for the first time. The Ag2HgS2 SCRs are technically investigated, and the study reveals that they are in high quality via the determination of their crystal structure, morphology, and optical properties. Density functional theory (DFT) calculations are carried out to explore more reliably details on the band structure of bulk Ag2HgS2. Meanwhile, a series of photodetectors based on the individual Ag2HgS2 SCRs are fabricated, and they convey sensitive responses to a 0.170 mu W cm(-2) weak light and unanimous responses to incident light with different wavelengths from 254 to 980 nm. In addition, the devices show excellent detecting performances without any obvious slump after the Ag2HgS2 SCRs exposed in air over 18 months.

Automated summary

This study successfully fabricated Ag2HgS2 single crystal rods (SCRs) with high quality and stability, analyzed via technical investigations and density functional theory calculations. The photodetectors based on the individual Ag2HgS2 SCRs exhibited sensitive responses to incident light with different wavelengths, demonstrating consistent performance and stability even after long-term exposure in air.