Photoluminescence study of ZnMgO films fabricated by using the atomic layer deposition method

Zn1-xMgxO films with various Mg contents were fabricated by using the atomic layer deposition technique. The optical properties of the Zn1-xMgxO films were analyzed by using photoluminescence (PL) measurements for various of temperatures (5 K ∼ 300 K). For low-temperature PL measurements, as the Mg content was increased, the peak transition energy of the bound exciton increased due to band-gap expansion which enabled us to evaluate Mg content (x). As the temperature was raised, a pronounced blue-shift was observed due to the transformation from a bound to a free exciton by the absorption of thermal energy.