A new approach to grow polycrystalline CuGaSe2 thin films:: Chemical vapor deposition with I2 as transport agent

Polycrystalline CuGaSe2 thin films have been prepared onto glass by a chemical vapor deposition (CVD) method which uses iodine as the transport agent. The source material was a polycrystalline CuGaSe2 powder which was pressed into pellets. Single phase CuGaSe2 films were prepared in a temperature range from 460 degrees C to 560 degrees C and had grain sizes between 0.5 and 5 mu m. Thermochemical calculations were performed for the system under equilibrium conditions to model the deposition process, The necessary values for the heat of formation H-298 and the standard entropy S-298 for CuGaSe2 were estimated to be H-298 = -251 kJ/mol and S-298 = 155 J/K mol. The calculations are in good agreement with the experimental observations.