189j Effects for TiO2 Structures In Dye Sensitized Solar Cell

Byoung-Jun Min¹, Bok-Min Kim¹, Seon-Gyun Rho², Sung-Yong Cho¹, Seung-Jai Kim¹, and Choon-Hyoung Kang³. (1) Department of Environmental Engineering, Chonnam National University, 300 Yongbong-Dong, Buk-ku, Gwangju, 500-757, South Korea, (2) BK21 Development of Envrionmentally Firendly Core Materials and Processes, Chonnam National University, 300 Yongbong-Dong, Buk-ku, Gwangju, 500-757, South Korea, (3) Department of Applied Chemical Engineering, Chonnam National University, 300 Yongbong-Dong, Buk-ku, Gwangju, 500-757, South Korea

Nanocrystalline TiO2 is now widely applied to dye-sensitized solar cells(DSSC) as a nanocrystalline structure which effectively delivers electrons injected from optically excited dye to the back contact. Further, more efficient photoelectrochemical performance of DSSC was demonstrated with the anatase TiO2 compared with the rutile-based DSSC. In this study, we investigated the effects of TiO2 morphology on the photovoltaic conversion efficiency of DSSC solar cell in a quantitative way.

For this purpose, TiO2 nanoparticles with varying content of rutile and anatase were prepared by using the sol-gel method from Titanium(IV) isopropoxide(TTiP) solution. DSSC with purely anatase DSSC showed by 2% higher conversion efficiency than the pure rutile DSSC. This is attributed to the less adsorbed amount of the dye due to the smaller surface area and the lower degree of interparticle connectivity of rutile TiO2. DSSC fabricated with TiO2 paste prepared by mixing anatase and rutile in the ratio of 9:1 showed a more efficient photoelectrochemical performance than DSSC with the TiO2 prepared in the ratio of 7:3.In General, the higher the anatase content, the higher the photovoltaic conversion efficiency. However, it is noteworthy that conversion efficiency levels off as the oxide morphology approaches the pure anatase form. In other words, the maximum photovoltaic conversion efficiency for varying contents of rutile and anatase was attained when the oxide morphology is somewhat between pure forms. This result can be explained in the way mentioned above.