The effect of electronegativity on optical properties of Mg doped ZnO

Abstract

In this work, ZnO thin films are deposited on glass substrates by sol gel spin coating technique and doped at different concentration of Mg (1%, 2%, 3%, 4%, and 5% Mg). The structural, morphological and optical properties of ZnO doped Mg are investigated for improved thin film solar cell performance. The DRX result exhibit that once the Mg atoms was introduced in the ZnO structure, the peaks take a preferential orientation according to the (002) plane, reaching a maximum value at 2% Mg. This behavior has been attributed simultaneously to the difference of electronegativity between Zn and Mg, and variation of grain size.The variation of electronegativity affected also the optical properties where the transmittance reaches its maximum value of 90%at 3% Mg concentration. The gap energy reaches the maximum value in a sample with the highest crystallite size and the highest preferential orientation, which corresponds, to ZnO: 2% Mg.