Characterisation of electrodeposited CdS films by phase modulated spectroscopic ellipsometry

CdS films were prepared on SnO2 coated glass substrates by the electrodeposition technique in an aqueous bath. Depositions were carried out at three different bath temperatures (50 degrees C, 70 degrees C and 85 degrees C) and at three different deposition potentials (-600mV, -620mV and -640mV measured w.r. t. Saturated Calomel Electrode). Films have been characterised by a state-of-the-art Phase Modulated Spectroscopic Ellipsometer in the wavelength range of 300-1000nm. The experimental ellipsometric data have been fitted with theoretically simulated spectra assuming a double-layer structure for CdS films and with appropriate dispersion relation for the optical constants of CdS. The reported optical data of electrodeposited CdS films would be very useful in exploring its fruitful applicability in CdS/CdTe solar cells and other optoelectronic devices.