Chemically deposited Sn-doped PbS thin films for infrared photodetector applications

Lead sulfide is a potential infrared (IR) photodetector material because of its favorable optoelectronic properties. The physical and chemical properties of PbS can be modified by a systematic doping of elements. In this study, we have doped 1-3 at% of Sn into PbS by a chemical bath deposition method. The undoped PbS films exhibited cubic crystal structure with a lattice parameter of a = 0.594 nm, an uneven grain growth, a direct optical band gap of 0.44 eV and a hole mobility of 8.9 cm(2) V-1 s(-1). The Sn-doping has improved the microstructure and slightly decreased the band gap of PbS. The hole mobility of PbS films has increased to 20 cm(2) V-1 s(-1) with Sn-doping (1-2 at%). Thus, the PbS films grown by Sn-doping with improved microstructure, decreased band gap, and increased electrical properties are beneficial for IR photodetector applications.

Automated summary

Doping of tin improves the microstructure and electrical properties of lead sulfide films, decreases the band gap, and increases the hole mobility. Tin-doped lead sulfide films are beneficial for infrared photodetector applications.