Ag₂S QDs/Si Heterostructure-Based Ultrasensitive SWIR Range Detector

In the 20^th century, microelectronics was revolutionized by silicon-its semiconducting properties finally made it possible to reduce the size of electronic components to a few nanometers. The ability to control the semiconducting properties of Si on the nanometer scale promises a breakthrough in the development of Si-based technologies. In this paper, we present the results of our experimental studies of the photovoltaic effect in Ag₂S QD/Si heterostructures in the short-wave infrared range. At room temperature, the Ag₂S/Si heterostructures offer a noise-equivalent power of 1.1 × 10^-10 W/√Hz. The spectral analysis of the photoresponse of the Ag₂S/Si heterostructures has made it possible to identify two main mechanisms behind it: the absorption of IR radiation by defects in the crystalline structure of the Ag₂S QDs or by quantum QD-induced surface states in Si. This study has demonstrated an effective and low-cost way to create a sensitive room temperature SWIR photodetector which would be compatible with the Si complementary metal oxide semiconductor technology.