Electronic structure of indium tungsten oxide alloys and their energy band alignment at the heterojunction to crystalline silicon

Abstract

The electronic structure of thermally co evaporated indium tungsten oxide films is investigated. The stoichiometry is varied from pure tungsten oxide to pure indium oxide and the band alignment at the indium tungsten oxide crystalline silicon heterointerface is monitored. Using in system photoelectron spectroscopy, optical spectroscopy and surface photovoltage measurements we show that the work function of indium tungsten oxide continuously decreases from 6.3 eV for tungsten oxide to 4.3 eV for indium oxide, with a concomitant decrease of the band bending at the hetero interface to crystalline silicon than indium oxid