| SM ISO690:2012|
DERMENJI, Lazari; CURMEI, Nicolai; GUC, Maxim; GURIEVA, Galina; RUSU, Marin; FEDOROV, Vladimir; BRUC, Leonid. Effect of annealing on the composition of CZTSSe thin films obtained by spray pyrolysis. In: Materials Science and Condensed Matter Physics. Editia a 8-a, 12-16 septembrie 2016, Chişinău. Chişinău: Institutul de Fizică Aplicată, 2016, p. 187. ISBN 978-9975-9787-1-2.
|Materials Science and Condensed Matter Physics
Editia a 8-a, 2016
Conferința "International Conference on Materials Science and Condensed Matter Physics" |
8-th Edition, Chişinău, Moldova, 12-16 septembrie 2016
The problem to reduce the cost of photovoltaic conversion of solar energy and to exclude the toxic and rare chemical elements (Cd, Ga, In) in the production of solar panels has become actually and very important in recent years. Solar cells with active absorbing component on the base of Cu2ZnSn(S,Se)4 kesterite films demonstrates efficiency more than 12% . The aim of this work is the investigation of the composition of CZTSSe kesterite films, obtained by spray pyrolysis, in dependence on the composition of the initial solutions components, geometric and thermal parameters of the deposition. Thin kesterite Cu2ZnSnS4 layers were prepared by spray pyrolysis method from a stock solution, obtained by mixing the two precursor solutions containing thiourea. 25 ml of the aqueous solution of the precursors №1 contain 1.9 g of thiourea and 0.83 g of CuCl2. 25 ml of the aqueous solution of the precursors №2 contain 1.9 g of thiourea and 4.38 g of SnCl4 5H2O and 2.75 g Zn (O2CCH3)2 2H2O. The starting solution for spray pyrolysis was prepared by mixing 140 ml of water, 20 ml of the solution of the precursor №1and 80 ml of ethanol. Then, to this solution were added 8 ml of the solution of the precursor №2 and 4 ml of ethanol. This procedure of preparing the starting solution for spray pyrolysis allows minimizing the appearance of insoluble hydrates and cuprous chloride leads to the formation of CZTS stoichiometric films. The optimum substrate temperature for obtaining these films was ~ 350° C, and the distance to the nozzle atomizer ~ 30cm. The lack of the sulfur in the obtained CZTS films was eliminated by annealing at a temperature of 525oC at about 10-2Torr static vacuum for 30 minutes in an S2 atmosphere with added tin. Then the same annealing of the films in the atmosphere S2 + Se2 was made. The morphology and chemical composition of the obtained thin films were investigated by energydispersive x-ray spectroscopy and Raman scattering method. Structural studies by grazing incidence of the beam (GIXRD) showed the presence of Cu2-xS phase in all samples. For thin films annealed in the atmosphere (S2 + Se2), the ratio Se / (S + Se) was obtained from the chemical composition and structural analysis and both methods showed fairly close values.