The Electrical and Optical Properties of the System TiO(2-x)F(x). The Electrical, Optical and Photoconducting Properties of Fe(2-x)Cr(x)O3(O < or = x < or = 0.47).

摘要

A convenient method for preparing compounds in the system TiO(2-x)F(x) is described and the photoelectrolytic behavior of TiO(2-x) and TiO(2-x)F(x) anodes has been investigated. It was found that the substitution of small amounts of fluorine for oxygen in TiO2 increases the photocurrent output which arises from increased response at the longer wavelengths. The improved response may be attributed to the increase in depletion layer width which is supported by an observed increase in resistivity. A study has also been carried out on the electrical, optical and photoconducting properties of pure and reduced single crystals of the composition Fe(2-x)Cr(x)O3 where O < or = 0.47. It has been found that pure alpha-Fe2O3 is not a photoconductor. A necessary condition for the observation of photocurrents in n-type Fe2O3 is that some Fe3O4 be present. In addition, it has been found that the substitution of chromium for iron in alpha-Fe2O3 results in a montonically decreasing optical band gap as the chromium concentrations, x, increases. (Author)