Band-gap shift in indium tin oxide

In this work we report the optical transmittance properties of indium tin oxide (ITO) near the band-gap under different current injection conditions through a thin film. A narrowing of the band-gap is observed as a function of current, consistent with band-tailing effects associated with electron-electron and impurity scattering due to heavy doping in semiconductors. The absorption coefficient dependence on photon energy is verified to be consistent with an M/sub 0/ Van Hove type of discontinuity in the density of states function.