Synthesis of Tungsten Oxide Particles by Chemical Deposition Method

抄録

Due to the high potential of photoconductive behavior used in electrochromic and sensor devices, tungsten oxide (WO₃) is the most promising candidate applied for electrochromic materials, gas sensors, and dye sensitized solar cells. Adsorbing the visible blue light by tungsten oxide nanoparticles would thus be used efficiently to enhance the sun-light harvest efficiency. Recent investigations have been promoted by new methods of ultrafine powder production and their applications. Nanocrystalline tungsten oxide can be prepared by sputtering methods, gas condensation methods, and chemical deposition method. In this study, we would like to prepare of tungsten oxide nanoparticles by chemical deposition method and investigate the experimental parameters of various organic solutions and discuss the relationship between absorbance spectra and which by chemical deposition method. Purged O₂ into the various solvent (i.e. DMF and acetylacetone solution), WCl₆ was added into the solvent slowly and stirred vigorously. During the filtration process solutions were characterized and analyzed by particles size distribution, UV-visible absorption, and TEM observation. The size of tungsten oxide particles synthesized in DMF is smaller than that in acetylacetone solutions from TEM observation. These results may be related to particle sizes or agglomerated behavior of tungsten oxide. In the photochromic data, it exhibits absorbance result due to valence change of tungsten ion and photochromic effect of tungsten oxide nanoparticles. Since some papers also have been reported that the highest intensity of the solar spectrum is in the blue region, the modification of the oxide semiconductor for blue-light absorption will effectively increase the photon harvest from the incident sunlight and thus generate more electron-hole pairs in addition to those from dyes. It would be appropriately applied in the design of solar cell devices.