Performance analysis of graphite and multi wall carbon nanotube based counter electrodes in dye sensitized solar cells

Abstract

In this research work, a new type of cost-effective metal-free counter electrode for dye sensitized solar cell is introduced. This new type of solar cell is environment friendly in nature which has been investigated by the researchers. Recently DSSC is becoming very popular due its organic nature and its flexible application in various fields. It can be integrated in building integrated photovoltaic cell, act as a window glass, can be a portable charger for electronic gadgets. The overall structure of the cell is a sandwich-like formation that has photo sensitized anode in the first part and counter electrode at the end. Here 4 types of counter electrode is prepared by doctor blade technique where graphite and multi-wall carbon nanotube mixture follows 4 different ratios of 0:3, 3:0, 3:1 and 3:1 (with PEG) on a 2×1.6 cm 2 indium-doped tin oxide substrate. The counter electrode is expected to show enhanced electro catalytic characteristics toward reduction reaction as well as low charge-transfer resistance at the counter electrode-electrolyte interface. In combinationwith a natural dye (Indian Blackberry), dye-sensitized TiO photo anode and a liquid electrolyte, the fabricated counter electrode DSSCs show 0.041%, 0.006%, 0.0139% and 0.0832% energy conversion efficiencies under 1 sun illumination (100mW/cm 2 , 1.5AM). The data is comparable to the efficiency of the DSSC with platinum electrode that is 0.01% under the same experimental conditions. Hence the finding suggests that graphite and MWCNT (with PEG) ratio of 3:1 is a promising alternative counter electrode for low cost dye sensitized solar cells.