Effect of annealing temperature and laser pulse energy on the optical properties of CuO films prepared by pulsed laser deposition

In this work; copper oxide films (CuO) were fabricated by PLD. The films were analyzed by UV-VIS absorption spectra and their thickness by using profilometer. Pulsed Nd:YAG laser was used for prepared CuO thin films under O2 gas environment with varying both pulse energy and annealing temperature. The optical properties of as-grown film such as optical transmittance spectrum, refractive index and energy gap has been measured experimentally and the effects of laser pulse energy and annealing temperature on it were studied. An inverse relationship between energy gap and both annealing temperature and pulse energy was observed.

Bandgap Determination of Cubic Rocksalt AlN Film from Experimental and Theoretical Investigations

Cubic rocksalt (RS) AlN film was grown on MgO (100) substrate by laser molecular beam epitaxy (LMBE) technique, and its bandgap was determined experimentally and theoretically. Based on the analysis of optical transmittance spectrum, the RS AlN film shows an indirect bandgap of 4.807 eV. Using the Cambridge sequential total energy package (CASTEP) module of materials studio (MS) software, an indirect bandgap of RS AlN is predicted as observed experimentally. While the calculated bandgap is smaller than the experimental value, which can be ascribed to the inaccurately handled exchange-correlation energy in the calculations.