PREPARATION AND CHARACTERIZATION OF CIS POWDERS BY A FACILE REFLUXING REACTION ROUTE

CuInSe 2 (CIS)-based powders were successfully prepared by a facile refluxing reaction route using metal halides and Se / S powder as raw starting materials. The phase and crystallographic structure, morphology, chemical composition of the products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS). It is found that single phase CIS powders with chalcopyrite structure can be prepared in a relatively short time using triethylenetetramine as the solvent; the most suitable reaction temperature and time are 200°C, 1–2 h, respectively. CuIn ( S x Se 1-x)2 powders were also prepared by refluxing reaction route using the mixed solvent of triethylenetetramine–glycol (1:1, v/v). The characterizations showed that the CuIn ( S x Se 1-x)2 has single chalcopyrite phase, and the stoichiometric composition closely follows the primary mixed ratio. The morphology of CuIn ( S x Se 1-x)2 is close to spheres, and the particle sizes become distinctly smaller with the incorporation of S . A possible formation mechanism of CuInSe 2 was put forward and briefly discussed.

SPUTTERED TiO2 FILMS FOR PHOTOVOLTAIC CELL'S ANTIREFLECTION COATING

TiO2 films were prepared by the magnetron sputter system with various oxygen partial pressure ratios, for the application of photovoltaic (PV) cells, TiO2 single-layer and SiO2/TiO2 double-layer antireflection (AR) coatings were deposited on Si substrate. The experimental results indicate that TiO2 film deposited at oxygen partial pressure ratio of 15.4% exhibits smooth surface morphology, amorphous structure, and good optical transmittance, which is suitable for AR coating in the PV cell structure system. Furthermore, the weighted average reflectance in the range of 400–900 nm was about 10.3% and 3.7% for the TiO2 single-layer and SiO2/TiO2 double-layer AR coatings, respectively. With a double-layer AR coating, a 50.8% improvement in the efficiency of a Si PV cell was achieved.