Improvement of the Crystallinity of MgZnO with a Zn Buffer Layer by Sol-Gel Spin-coating Method

We fabricate magnesium zinc oxide (MZO) thin films inserting a buffer layer between a film and a substrate with different annealing temperatures. The structural and optical properties of MZO thin films are investigated by using scanning electron microscopy, X-ray diffraction (XRD), and photoluminescence. The XRD patterns for the buffer layers annealed at 200 degrees C show the narrowest full width at half maximum and the most intense (002) diffraction peak. In addition, the buffer layers decrease the magnitude of the residual stress between the MZO thin film and the silicon substrate. The near-band-edge emission peaks intensify and the deep-level emission peaks significantly intensify with increasing buffer layer annealing temperatures. Inserting a buffer layer between a film and a substrate improves the crystallinity of MZO thin films.