Theoretical and Experimental Study of a Dye-Sensitized Solar Cell

Abstract

Theoretical and experimental analyses of the performance of a dye-sensitized solar cell (DSSC) are presented. Using a macroscopic first-principles mathematical model of the DSSC, the effective electron diffusion coefficient, recombination rate constant, and difference between the conduction band and formal redox potentials are estimated from current–voltage (I–V) measurements. The mathematical modeling indicates that (i) diffusion is the dominant driving force for the transport of electrons and holes, and thus electric-field-induced migration can be neglected; (ii) the type of recombination rate equation has little effect on the estimates of the effective electron diffusion coefficient and the difference between the conduction band and formal redox potentials; (iii) the recombination rate constant affects both the cell open-circuit voltage and short-circuit current; (iv) the conduction band edge movement affects mostly the cell open-circuit voltage; (v) as expected, the I–V performance of the cell changes very little with operating temperature variations; and (vi) the effects of different light absorbers on the cell I–V performance is through the absorption coefficient and displacement of the conduction band. The transient behavior of the cell from the dark equilibrium conditions to short circuit conditions and the cell transient response to a step change in the external load are investigated theoretically. Experimental I–V results from a DSSC, under different light intensities and with two different dyes, are used to validate the model.