Authors:
N. Mitoma, B. Da, H. Yoshikawa, T. Nabatame, M. Takahashi, K. Ito, T. Kizu, A. Fujiwara, K. Tsukagoshi

Abstract:
The enhancement in electrical conductivity and optical transparency induced by a phase transition
from amorphous to polycrystalline in lightly silicon-doped indium oxide (InSiO) thin films is studied.
The phase transition caused by simple thermal annealing transforms the InSiO thin films from
semiconductors to conductors. Silicon atoms form SiO4 tetrahedra in InSiO, which enhances the
overlap of In 5s orbitals as a result of the distortion of InO6 octahedral networks. Desorption of
weakly bonded oxygen releases electrons from deep subgap states and enhances the electrical conductivity
and optical transparency of the films. Optical absorption and X-ray photoelectron spectroscopy
measurements reveal that the phase transition causes a Fermi energy shift of 0.2 eV.

Link:
Appl. Phys. Lett. 109 (2016) 221903.
DOI: 10.1063/1.4968810