Characteristics and Deposition of CuInS2 film for thin solar cells via sol- gel method

CuInS2 thin films were prepared using a sol-gel spin-coating method. That makes large scale substrate coating, simple equipment, easy composition control available. The structural and optical properties of CuInS2 thin films that include less toxic materials (S) instead of Se, tetragonal chalcopyrite structure. Copper acetate monohydrate (Cu(CH3COO)(2) . H2O) and indium acetate (In(CH3COO)(3)) were dissolved into 2-propanol and 1-propanol, respectively. The two solutions were mixed into a starting solution. The solution was dropped onto glass substrate, rotated at 3000 rpm, and dried at 300 degrees C for Cu-In as-grown films. The as-grown films were sulfurized inside a graphite container box and chalcopyrite phase of CuInS2 was observed. To determine the optical properties measured optical transmittance of visible light region (380 similar to 770 nm) were less than 30 % in the overall. The XRD pattern shows that main peak was observed at Cu/In ratio = 1.0 and its orientation was (112). As annealing temperature increases, the intensity of (112) plane increases. The unit cell constant are a = 5.5032and c = 11.1064 angstrom, and this was well matched with JCPDS card. The optical transmittance of visible region was below than 30 %.