Characterization of jet nebulizer sprayed CdO thin films for solar cell application

The highly transparent conducting cadmium oxide (CdO) films were prepared by jet nebulizer spray pyrolysis. Characterization and optimization of CdO films have been scrutinized using various techniques such as X-ray diffraction (XRD) pattern, scanning electron microscope (SEM), energy dispersive analysis by X-ray (EDAX) spectroscopy, Atomic force microscopy (AFM), ultraviolet visible (UV-Vis) spectroscopy, hall Effect and current–voltage (I–V) characteristics. The sample prepared at 400 °C with 4 ml and 0.20 M of volume and concentration of the precursor solution respectively have the transmittance of about 70% with a band gap of 2.37 eV and the resistivity was found to be a minimum of 3.38 × 10−3 Ω cm. The XRD, SEM and AFM studies have implied the presence of CdO nanocrystallites with cubic structure and having smooth surface. The short circuit current (Isc) = 5.90 mA/cm2 and open circuit volatge (Voc) = 429.3 mV values were established to be the maximum for the cell made with CdO films at 400 °C. The fill factor (FF) = 0.32 and conversion efficiency η = 0.8% was also maximum for this solar cell. The low fill factor and efficiency might be due to the formation of excess silicon dioxide (SiO2) at the CdO/p-Si interface due to reaction between CdO and Si at 400 °C.