Development of Low-Temperature Coating Process for Dye-Sensitized Solar Cell Titanium Layer

In 1991, Swiss scientist M. Grätzel initially reported a new solar cell structure. The so-called Dye-Sensitized Solar Cell (DSSC) had a sandwich configuration and the major part was the TiO2 porous layer doped with light-sensitive N3 dyes. The solar-to-electric energy conversion efficiency was approximately 7 %. Since the production cost of DSSCs was much less than other type solar cells, many researchers were devoted into the DSSC R&D work and recent development in DSSC showed that the conversion efficiency was over 10% using liquid electrolyte. The commercialization of DSSC is promising and hence the study of a large-area and crack-free 10 μm coated porous TiO2 film is urgently needed. The collaborative industrial partner, Glory-Sun Ltd., has the core technology in coating process and is currently one of the major diffuser suppliers to AUO. This project will apply the roll-to-roll coating process and study the low-temperature TiO2 film coating process on the flexible ITO/PET substrate. Ordinary DSSC TiO2 layer has to undergo a typically 400ºC or above sintering process, which is not favor to continuous ITO/PET coating process. Professor Yoshida’s group at Gifu University, Japan developed a novel room-temperature method for the preparation of porous TiO2 film with high performance in DSSCs (Adv. Func. Mater. (2006), 16, 1228). In this project, we will use their formula for coating paste. We will condition the ethanol-based coating paste and adjust the coater operating parameters to obtain a flat, crack-free, aggregate-free TiO2 film on ITO/PET. Bad coating causes wrinkle and aggregate formation and hence reduces the DSSC conversion efficiency and therefore, the operating windows for different coating methods will also be investigated.

Project ID:PB9709-4607
External Project ID:NSC97-2622-E182-002-CC3