Effects of the sulfidation temperature on the structure, composition and optical properties of ZnS films prepared by sulfurizing ZnO films
Abstract
Nanocrystalline ZnS films have been prepared by sulfidation of the reactive magnetron sputtered ZnO films. The structure, composition and optical properties of the sulfurized ZnO films as a function of the sulfidation temperature (TS) have been systematically studied. It is found that at TS ⩾ 400 °C ZnO is completely converted to ZnS with the hexagonal structure. The ZnS films have a strongly (0 0 2) preferred orientation and an optical transparency of about 80% in the visible region. In addition, at TS < 444.6 °C (boiling point of sulfur), some residual sulfur decomposed from H2S gas can adhere to the sulfurized film surface while at TS = 580 °C a S/Zn ratio much higher than the ideal stoichiometric proportion of ZnS is obtained for the ZnS films. ZnS films with a minimum XRD FWHM value of 0.165° and a good S/Zn ratio of 0.99 are obtained at a temperature of 500 °C indicating the ZnS films to be suitable for use in the thin film solar cells.
- Publication:
-
Optical Materials
- Pub Date:
- December 2004
- DOI:
- 10.1016/j.optmat.2004.03.020
- Bibcode:
- 2004OptMa..27..419Z
- Keywords:
-
- ZnS;
- Sulfidation;
- ZnO;
- Solar cells;
- 78.66.Hf;
- II-VI semiconductors