CU_2ZNSNS_4 THIN FILM SOLAR CELLS PRODUCED VIA SOL GEL WITHOUT SULFURIZATION AND OPTIMIZATION THE ANNEALING TEMPERATURE

摘要

Cu_2ZnSnS_4 (CZTS) thin films were synthesized by spin coating on soda lime glass (SLG) substrates and SLG substrates covered by molybdenum using the sol-gel method, without a further sulfurization step. The thin films were subsequently annealed under different temperature ranging from 350°C to 550°C for 1h in a nitrogen N_2 gas atmosphere. The effect of the annealing temperature on the properties of CZTS was systematically investigated. X-ray Diffraction (XRD) studies revealed that the as-deposited films and those annealed present the (112), (220), and (312) diffraction peaks that are characteristic of the kesterite phase. The optimum temperature annealing found to be 470°C, and the crystallite size increases with annealing temperature. The band gap energy of CZTS thin films changed in the range of the 1.85eV to 1.48eV upon varying the annealing temperature. The first SLG/Mo/CZTS/ CdS/i-ZnO/AZO/Al-grid solar cells that were fabricated showed an open-circuit voltage of 140 mV and short-circuit current of 0.63mA/cm~2. These results demonstrate the CZTS thin films can be successfully deposited by a low cost sol-gel technique.