OPTICAL-PROPERTIES OF RF REACTIVE SPUTTERED TIN-DOPED IN2O3 FILMS

The optical effective mass of tin-doped In2O3 films prepared by r.f. reactive sputtering has been determined from measurements of the plasma resonance frequency in the near-infrared region and the refractive index in the visible region. It is found that the optical effective mass changes from 0.31m0 to 0.43m0 when the carrier concentration is increased from 1.0 × 1019 t0 8.2 × 1020 cm-3, where m0 is the electron rest mass. With increase in the carrier concentration the shifts of the absorption edge due to the direct and to the indirect transition were measured in the near-ultraviolet region. The results are discussed in terms of the effective mass and the band structure of the In2O3 crystal. © 1979.