Lead-based chalcogenide thin films for mid-IR photoreceivers: plasma synthesis, semiconductor, and optical properties

Abstract

Complex chalcogenide systems like PbS1-xSex seem to be promising semiconductors with a great potential for highly sensitive photodetectors of the mid-IR range and thermoelectric working at room temperature. The first group of problems that scientists face is how to synthesize materials with a homogeneous chemical and phase composition and a well-defined stoichiometry. The second is how to avoid contamination of such sensitive materials with residues of unreacted precursors and installation materials. In addition, the technological approach should allow the potential scale-up of the process for commercial applications of the above materials. In this work, we report the applicability of the plasma-enhanced chemical vapor deposition (PECVD) in preparation of PbS1-xSex complex inorganic chalcogenide materials of various stoichiometry and phase composition in function of plasma process conditions. Elemental high-pure lead, sulfur, and selenium were the initial substances. RF (40.68 MHz) non-equilibrium plasma discharge at low pressure (0.01 Torr) was used for the initiation of interactions between the starting materials. The PECVD process was studied by optical emission spectroscopy (OES). Various analytical methods were utilized to characterize the obtained materials.