Microwave-assisted chemical bath deposition of PbSe thermoelectric thin films

By using microwave-assisted chemical deposition (MA-CBD) technique, lead selenide (PbSe) thin films were successfully synthetized at 80 degrees C and different growth times (3, 4, and 5 min). The films were analyzed by means of X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and UV-Vis spectroscopy. Also, their electrical properties, such as conductivity, Seebeck coefficient, carrier concentration, and carrier mobility, are presented. Homogeneous films with thickness in the range 120-165 nm and gran size of 22.9-24.5 nm were obtained. The dislocation density and micro-strains were found to vary inversely proportional to the crystallite size. Three and five-element thermocouples were tested with thermoelectric potential of up to 1.59 mV K-1. The values of energy band gap of 0.75-0.64 eV, electrical conductivity of 9-28 omega(-1) cm(-1) and Seebeck coefficient of 213-232 mu V K-1 suggest that MA-CBD is an effective synthesis technique to produce PbSe thin films for photovoltaic and thermoelectric applications.