The effect of illumination direction and temperature on dye-sensitized solar cells with viscous cobalt complex-based electrolytes

Abstract

The illumination direction and temperature can greatly affect the performance of dye-sensitized solar cells (DSSCs) when practical non-volatile solvents are used with bulky one-electron redox mediators such as cobalt tris(bipyridine). For higher performance, a tandem electrolyte system consisting of cobalt tris(bipyridine) with tris(4-methoxyphenyl)amine was used. Discrepancies in J-V hysteresis were investigated by using photocurrent turn-on transients, open-circuit voltage decay, and electrochemical impedance spectroscopy. The devices perform much better upon illumination form the counter electrode side and exhibit much less hysteresis and more stabilized power output as characterized by maximum power-point tracking (MPP) tracking.