The efficiency effect of dye sensitized solar cell using different ratio of organic polymer doped titanium dioxide at different annealing process temperature

Abstract

Titanium Dioxide (TiO2) is one of the main materials in Dye Sensitized Solar Cell (DSSC). It is well known with its property of good optical transmittance and its mesoporous surface that can absorb generous amount of dye. In this study, TiO2 is fabricated using spin coating technique that leads to the uniform thickness of TiO2 layer. The thickness of the TiO2 can be controlled layer by layer using same technique to get an optimized surface that can lead to better performance of DSSC. In order to achieve this, the surface roughness of TiO2 must be as high as possible. Therefore, the organic material which is Poly(2-methoxy-5-(2’-ethylhexyloxy)-1,4-phenylene-vinylene (MEH-PPV) is used as medium to increase the mesoporous roughness structure of TiO2 nanocrystal film for DSSC. MEH-PPV is doped into the TiO2 using 0.5 mg/ml with different temperatures of 100℃ and 450°C. Different temperatures of MEH-PPV will lead to the different surface structures for TiO2 thin film. The ratio of TiO2:MEH-PPV used were 1:1 and 2:1. The surface of TiO2 thin film was characterized using Atomic Force Microscope (AFM). The efficiency was obtained using Solar Simulator based on the voltage and current flow. Based on the results, the increment of surface roughness is about 21% for the different ratio at various temperatures. The optimum temperature and suitable ratio of TiO2:MEH-PPV was obtained via annealing process at 450℃ with the ratio of 2:1. It gives the highest efficiency which is 0.1266%. These two important findings yield good mesoporous surface of TiO2 thin film.