Structural and optical characterization of cadmium, magnesium, zinc oxide (CdMgZnO) sputtered thin film deposited on three different substrates

CdMgZnO thin films deposited on three different substrates (Glass, ITO, and Silicon) were fabricated using the radio frequency (RF) magnetron sputtering technique. The thin films were of hexagonal wurtzite structure with high crystallinity. Optical transmittance of the thin films exhibited high transparency in the visible range, 77.01 %–89.92 %, while CdMgZnO/Glass film had the least energy band gap of 3.20 eV, and CdMgZnO/Si the largest 3.37 eV. FESEM images revealed nearly spherical non-porous grains with the silicon substrate film (CdMgZnO/Si) exhibiting the highest uniformity. Surface roughness attributed to thermal strain from AFM images found (CdMgZnO/Glass) was the roughest (16.43 nm), while (CdMgZnO/Si) had the least average roughness (13.48 nm). A direct proportionality relation exists between the grain size of the thin films, their light transmittance, and absorption edge, and that for CdMgZnO/Si>CdMgZnO/Glass >CdMgZnO/ITO, where CdMgZnO/ITO film with the least transmittance implies a high absorption coefficient of 4.2 × 10 5 cm −1 of the film in solar cells and photosensor applications.