Application Of CuI In Dye-Sensitized Solar Cell

CuI, a hole transport material, was successfully used in this thesis to fabricate the solid state dye-sensitized TiO₂ nanocrystalline thin film solar cells (TiO₂/dye/CuI/Pt), where the screen-printing method was used to prepare the TiO₂ nanocrystalline thin film in the presence of polystyrene spheres (PS) which acted as the hole-maker. Factors that affect the photoelectrochemical performance of the TiO₂/dye/CuI/Pt cells were investigated, and the conditions for preparing the cell were optimized.1. TiO₂ nanocrystalline thin films was obtained by screen-printing method, where polystyrene spheres (PS) was added to create large pores within the films. The effect of diameter and the amount of PS on the properties of TiO₂/dye/CuI/Pt cell were investigated, and the best light to electric conversion efficiency was obtained in case of PS with 200 nm in diameter and 10% in weight was used.2. The factors such as compact layer, platinized counter electrode and the ratio of ion liquid in electrolyte were systematically investigated.3. The in-situ deposition method was induced to prepare CuI hole transport layer in TiO₂/dye/CuI/Pt cells. This leads the large increase of hole transport rate in the cell as compared to that of the solution based ex-situ deposition route, owing to its lower interfacial resistance resulting from better contact between CuI layer and nanocrystalline porous thin film.4. As the in-situ route can provide better TiO₂/CuI contact while ex-situ method bring more CuI into TiO₂ film, in-situ and ex-situ methods was combined to form the TiO₂/dye/CuI/Pt cell. As the result, large increase of the energy conversion efficiency for the resulted solid-state solar cell was obtained.