PbSe sensitized with iodine and oxygen: a combined computational and experimental study

Abstract

Lead selenide (PbSe) is one of the most promising materials for the uncooled mid-IR detectors. Sensitization of PbSe consists of thermal treatment in the oxygen/iodine atmosphere, and was experimentally examined before. However, there were no computational studies supporting the experiments. Density functional theory (DFT) calculations have been applied for better understanding of the influence of iodine and oxygen dopants have on PbSe crystal lattice, band structure, conductance. Calculations proved that oxygen induces a more robust effect on band structure, while iodine reduces work function, increasing surface reactivity. Structural characterizations confirmed the crystallization of the lead selenite phase, during sensitization in oxygen, while the new Pb3Se2(IO3)2 phase crystallized during sensitization in iodine/oxygen rich atmosphere. U/I characterization confirmed IR sensitivity of the samples treated at 400 °C in oxygen rich atmosphere for 3 h, and for the samples treated in the iodine/oxygen rich atmosphere at 375 °C for just twenty minutes.