Solvent volume dominated improved Haacke’s quality factor values realized for CdO:Mo thin films well suited for optoelectronic applications

Solvent volume has profound influence on the structural, morphological and optoelectronic properties of spray deposited thin films. In this work solvent volume (20, 30, 40, 50 and 60 mL) impact on the optoelectronic properties of spray deposited molybdenum doped cadmium oxide (CdO:Mo) has been reported. XRD reveals cubic crystal structure of the CdO:Mo thin films. Crystallite size increases with solvent volume up to 50 mL and for the 60 mL it decreases. SEM images show cauliflower shaped grains. EDX spectra revealed Cd, Mo and O in all the films. Thickness dominated the UV–Vis-NIR properties of the films. The increased band gap values with increased solvent volume are attributed to the Burstein-Moss effect. The 50 mL solvent volume coated film exhibited increased transparency, low sheet resistance (21.6 Ω/□), low resistivity (0.93 × 10 –3 Ω-cm) and high figure of merit value (1.15 × 10 –2 Ω −1 ). Fabrication of a photodiode with p-Si/n-CdO:Mo/Ag heterostructures is done to study its photo response behaviour.