High mobility In2O3:H transparent conductive oxides prepared by atomic layer deposition and solid phase crystallization

The preparation of high-quality In2O3:H, as transparent conductive oxide (TCO), is demonstrated at low temperatures. Amorphous In2O3:H films were deposited by atomic layer deposition at 100 °C, after which they underwent solid phase crystallization by a short anneal at 200 °C. TEM analysis has shown that this approach can yield films with a lateral grain size of a few hundred nm, resulting in electron mobility values as high as 138 cm2/V s at a device-relevant carrier density of 1.8 × 1020 cm–3. Due to the extremely high electron mobility, the crystallized films simultaneously exhibit a very low resistivity (0.27 mO cm) and a negligible free carrier absorption. In conjunction with the low temperature processing, this renders these films ideal candidates for front TCO layers in for example silicon heterojunction solar cells and other sensitive optoelectronic application