Photoelectric response in sandwich structures based on condensed layers of Ag2S quantum dots passivated with thioglycolic acid

Abstract

The study is aimed at developing a technique for forming a structure with a Schottky barrier in the form of a mltilayer Al-Ag2S-ITO sandwich structure, which includes a condensate of colloidal Ag2S quantum dots passivated with thioglycolic acid molecules (Ag2S/TGA QDs). The spectral properties were studied using a USB2000+ spectrometer (Ocean Optics, USA) with a USB-DT light source (Ocean Optics, USA). Electrophysical and photoelectric properties of the structures were studied using a Keysight B1500A semiconductor device analyzer (Keysight tech, USA). The study of the temperature dependences of the properties in the temperature range from 300 to 360 K was carried out in a Shielded room (Faraday cage) placed in a muffle furnace. It was found that the conductivity of the Al-Ag2S-ITO structure is mostly governed by the Schottky barrier at the Al-condensed Ag2S QDs film junction. At the junction between the condensed Ag2S QDs film and Al, signs of the formation of a rectifying contact were found. Under the action of the optical radiation with a wavelength of 650 nm and less, which corresponds to the most probable exciton transition in the UV-Vis absorption of Ag2S/TGA QDs, an increase in the current was found for the negative branch of the J-V curve.

Keywords

• silver sulfide
• activation energy
• charge carrier mobility
• conduction mechanisms
• schottky barrier