Amorphous CdO-In2O3 alloy thin films with high conductivity and transparency synthesized by sol-gel method

Abstract The growth of CdO-In2O3 amorphous oxide semiconductor alloys with high mobility in a wide composition range, suitable for many optoelectronic applications, has been previously reported using room temperature sputtering. In the present work, we synthesized Cd1−xInxO1+δ alloy thin films across the entire composition range using the non-vacuum, low-cost sol-gel spin coating method. Structural, electrical and optical properties of these alloy films were studied using a variety of analytical tools. We find that the alloy films become amorphous within the In composition range of 0.2   0.7 have the rocksalt CdO and bixbyite In2O3 structure, respectively. As-grown amorphous alloys have resistivity in the ranging from high 10−3 to low 10−2 Ω-cm due to their relatively low mobility of  85% over a wide transmission window of ~400–1600 nm can be achieved. The low temperature, low-cost non-vacuum processing, wide bandgap tunability, and low resistivity, make these sol-gel alloy films promising materials for optoelectronic applications, especially on organic layers and/or flexible substrates.