PREPARATION OF SPRAYED TIN OXIDE TRANSPARENT CONDUCTING FILMS AND THEIR STRUCTURAL AND ELECTRICAL-PROPERTIES

The aim of the present work was to prepare fairly uniform transparent and conductive tin oxide films using an inexpensive and easily controllable method. The technique adopted was spray deposition. The design of the spray deposition apparatus takes into consideration its reliability in controlling the different parameters affecting the formation of deposited layers, as well as its adaptability for large-area applications. The growth rate was independent of substrate type but increased with increasing substrate temperature. The crystalline structure of the films was found to be a function of substrate temperature and film thickness. The X-ray diffraction patterns showed that the preferred orientation was (110) and the grain size was in the range of a few tens of nanometres. The variation of sheet resistance with deposition parameters was studied and an empirical formula relating the sheet resistance to the film thickness was obtained. The prepared tin oxide layers of thicknesses up to 200 nm were found to have a transparency of about 80% to 85%, which makes them suitable for application as a single antireflecting coating of silicon solar cells. © 1990 Chapman and Hall Ltd.