Investigation of thin film cdte/cds solar cells with different layer thicknesses

With the rapid increase of the world population, the demand for energy is increasing day by day. Considering its usability, cleanliness and inexhaustibility as an alternative to depleted resources, solar energy comes to the forefront. Thin film solar cells can be produced with low cost and easy methods, while consuming a lot of energy and material in the purification process for the production of first generation silicon cells. Therefore, second generation thin film cells are the best alternative to first generation cells today. In this thesis, CdS and CdTe thin films were produced by ultrasonic spray pyrolysis (USP) method. Structural, morphological and optical properties of the thin films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis Spectrophotometer. In CdS thin film solution, cadmium chloride (CdCl2) was used as Cd source and thiourea ((NH2)2CS) compounds were used as S source. The prepared CdS solution was deposited on ITO coated glass substrates at a temperature of 380 °C. In CdTe thin film solution, cadmium chloride and tellurium dioxide (TeO2) were used as Te source. The prepared CdTe solution was deposited on two CdS / ITO coated glass substrates at a temperature of 350 ° C. SEM cross-sectional images of two different CdS thin film coatings with a production time of 10 and 20 minutes were deposited at 180 and 400 nm thickness on ITO coated glass substrates. The peaks of different planes on the X-ray diffraction plot of CdS thin films showed that the obtained CdS films were hexagonal. The main peak value of both CdS thin films is seen at 2θ = 28.20°, which is the characteristic peak of the CdS compound (101). The absorbance values of the obtained CdS thin films were measured by UV-Vis spectrophotometer in the wavelength range of 350 - 1100 nm and the band gaps were calculated as 2.45 eV for 180 nm film and 2.42 eV for 400 nm film. The results obtained were interpreted and recommendations were made for the production of more efficient CdS thin films by ultrasonic spray pyrolysis method.