CuAlO2 powder dispersed in composite gel electrolyte for application in quasi-solid state dye-sensitized solar cells

The use of delafossite CuAlO2 (CAO) powder as an additive in composite gel electrolyte (CGE) of the quasi-solid state dye-sensitized solar cell (DSSC) is first reported. In order to achieve an improvement of power conversion and long-term performance of the quasi-solid state DSSC, different contents of CAO powder containing in CGE, a mixture of polyethylene glycol (PEG), iodide/tri-iodide (I−/I3−) liquid electrolyte (LE) and 4-tertbutylpyridine (4-tBP), were used in the present study. The photocurrent density-voltage characteristic (J-V curve) and photovoltaic performance parameters of the cells, such as the short-circuit current density (Jsc), open-circuit voltage (Voc), power conversion efficiency (η) and fill factor (FF) were investigated. The CGE containing the dispersed CAO powder exhibited high ionic conductivity due to the charge diffusion through free channels. The power conversion efficiency of the quasi-solid state DSSC was significantly improved by adding CAO powder to the CGE. The optimum CAO powder content in the CGE was 0.05 wt%. In this research, the power conversion efficiency was 1.71 times of the LE and 2.85 times of the CGE with no CAO powder adding. The quasi-solid state DSSC based on the addition of CAO powder to CGE had long-term stability better than the normal DSSC based on the LE.