Improvement of CuO Thin Film Properties for High Mobility p-Channel TFT Applications

Abstract

In this work, the analysis of structural, optical, and morphological properties of CuO thin films deposited by the spin coating method has been done at different annealing temperatures to improve the properties of the material. When the annealing temperature increases, a slight variation in the CuO lattice parameter values has been observed, and the crystallite size was reduced from 34 nm to 27 nm. On the other side, the tail state defects are generated proportionally to the temperature in the CuO bandgap energy levels, increasing the energy bandgap to 1.63 eV for 500°C annealed thin film. The thin film’s surface roughness decreases from 3.5 nm to 3.3 nm, and the grain’s size reduces. As a result, the carrier scattering at the grain boundaries decreases, which improves the carrier mobility. Consequently, the enhancement in CuO thin film properties with respect to the annealing temperature has been observed, which is useful in device applications.