Abstract:

N type Hg3In2Te6 (short for MIT) single crystal is a new candidate semiconductor material for the fabrication of near-infrared photodetectors. Contact properties of MIT/metal were very important for the performance and reliability of MIT photodetectors. In this paper, the surfaces states of MIT wafers were analyzed by X-ray photoelectron spectroscopy (XPS) before and after H2O2 passivation. Moreover, the electrical characteristics of Au/MIT contacts were examined by currentvoltage ( I-V ) measurement. As a result, the binding energies of Te 3d 3/2, TeO2, TeO3 and In 3d 3/2 were 583 eV, 576.4 eV, 586.6 eV and 444.5 eV respectively, which didn’t changed after H2O2 passivation. However, the binding energy of Hg 4f increased about 0.15 eV and that of O 1s decreased about 0.18 eV after H2O2 passivation. Furthermore, the peak shape of O 1s turned symmetrical, which indicated the chemical states of O became stabilize on the MIT surface. Meanwhile, Te2- from MIT surface layer changed into Te0 and the HgO formed on the MIT surface after H2O2 passivation according to the following Formulas.