Computer modeling has become a necessity in the solar cells design. A computer model allows the study of the physical behavior of the device offering valuable information on the effects of each parameter on device performance. Dye-sensitized solar cells (DSSC) have attracted a lot of interest in recent years, in research as well as in industry. In present, the development has reached a stage where detailed physical models may contribute considerably to the optimization of these devices. Up to now, there is not a comprehensive model which links material parameters of a DSSC based on TiO₂ nanocrystals DSSC to the electrical performance of the whole cell, such as I-V characteristic and spectral response. Typically, a DSSC consists of two layers, a TiO₂ porous structure coated with a suitable light-absorbing charge-transfer dye wetted with an iodide/triiodide redox electrolyte and a bulk electrolyte layer, sandwiched between two glass substrates which are coated with transparent conductive oxide (TCO) layers. In this paper we present a model for the transport processes inside the DSSC based on the classical transport equations in one dimension. The equations are solved using the monodomain approach, which consists of using a single set of equations, with different values for the transport coefficients inside the two regions of the computational domain. The transport coefficients for the porous medium are calculated using homogenization techniques. The model permits the computation of the dye-sensitized solar cell I-V curves and efficiency. As model application, the influence of the most important material parameters on the cell performances investigated by numerical simulation is reported.

Date Published: 5 May 2008
PDF: 8 pages
Proc. SPIE 7002, Photonics for Solar Energy Systems II, 70020Y (5 May 2008); doi: 10.1117/12.779264

Published in SPIE Proceedings Vol. 7002:
Photonics for Solar Energy Systems II
Andreas Gombert, Editor(s)