| 초록 |
Copper zinc tin sulfide (Cu2ZnSnS4,CZTS) is a very promising material as a low cost absorber alternative to other chalcopyrite-type semiconductors based on Ga or In because of the abundant and economical elements. In addition, CZTS has a band-gap energy of 1.4~1.5eV and large absorption coefficient over ~104cm-1, which is similar to those of Cu(In,Ga)Se2(CIGS), one of the most successful absorber materials for high efficiency solar cell. Most previous works on the fabrication of CZTS thin films were based on the vacuum deposition such as thermal evaporation and RF magnetron sputtering. Although the vacuum deposition has been widely adopted, it is quite expensive and complicated. In this regard, the solution process using sol-gel precursor solution and nanocrystal inks have been developed for easy and cost-effective fabrication of CZTS film. However, the CZTS film prepared by solution process has generally poor crystallinity and small grains, resulting in performance degradation. Here, we report the effective method to fabricate the high crystalline CZTS film with large grain size by solution process. The CZTS films were annealed by tube furnace at different temperatures from 400 to 550oC. The cross-section of the CZTS films was investigated by the scanning electron microscopy (SEM). Successful fabrication of CZTS layer, reported here, is the first step in realizing the solution-processed CZTS solar cell with high efficiency. |
