Amorphous and crystalline In2O3-based transparent conducting films for photovoltaics

We reported solar cells with reduced electrical and optical losses using hydrogen-doped In2O3 (In2O3:H) transparent conducting layers with low sheet resistance and high transparence characteristics. The transparent conducting oxide (TCO) films were prepared by solid-phase crystallization of amorphous (a-) In2O3:H films grown by magnetron sputtering. The polycrystalline (poly-) In2O3:H films exhibited electron mobilities (over 100 cm2V−1 s−1) 2 and 3 times greater than those of conventional TCO films. This paper describes (i) the current status of the electrical properties of In2O3-based TCO; (ii) the structural and optoelectrical properties of the a-In2O3:H and poly-In2O3:H films, focusing on the inhomogeneity and stability characteristics of the films; and (iii) the electrical properties of bilayer TCO. The potential of these high mobility TCO films for solar cells was also described.