OPTICAL BAND GAP EXCITATION AND PHOTOELECTRON GENERATION IN TITANIUM DIOXIDE-BASED SOLID STATE SOLAR CELLS

Abstract

The properties and optical band gap excitation of nanoporous titanium dioxide ( TiO 2) and transparent semiconducting copper iodide ( CuI ) films prepared by a XeCl excimer laser were investigated. The CuI films exhibited optical transmittance over 80% in the wavelength range from 400 to 900 nm with minimum resistivity of about 2 KΩcm. The optical absorption of these films showed a remarkable blue shift compared to that of polycrystalline of CuI , which can be explained from the formation of ultra fine of CuI grains. The properties of pulsed laser deposited CuI and TiO 2 in power output of p- CuI | dye |n- TiO 2 cells were studied. The photoelectron generation and mechanism in fabricated p- CuI | dye |n- TiO 2 cells were also studied. An efficient charge generation was observed through the illumination of the TiO 2 layer of the fabricated p- CuI | dye |n- TiO 2 cells. The band gap excitation of TiO 2 was observed only under illumination through TiO 2 layer. The adsorbed dye molecules to the TiO 2 surface act as a relay, especially under illumination through TiO 2 layer in the wave range region of 300–400 nm.