Synthesis and optical properties of Mn doped ZnO thin films

Study of optical and electrical properties of Mn doped ZnO films deposited by atmospheric barrier torch discharge technique on SiO2 substrates is reported for a wide range of Mn concentration (0.2–20 at.%). It was found that the growth of all Mn‐doped ZnO films contains secondary Mn2O3 phase even for the lowest manganese concentration (0.2%). When Mn concentration is in the range 0.2–4%, this secondary Mn2O3 phase does not conspicuously affect Raman spectra of ZnO evidencing that Mn is mostly incorporated into the ZnO host matrix. Increase of Mn concentration (8–20%) is accompanied by formation of Mn2O3 clusters manifesting itself in the appearance of a corresponding mode in the Raman spectra. These clusters influence dramatically optical and electrical properties of the films. The Mn “solubility limit” for the films growth technique used is determined to be near 8%.