Combination of optical and electrical loss analyses for a Si-phthalocyanine dye-sensitized solar cell.

In order to promote the development of solar cells with varying types of sensitizers including dyes and quantum dots, it is crucial to establish a general experimental analysis that accounts for all important optical and electrical losses resulting from interfacial phenomena. All of these varying types of solar cells share common features where a mesoporous scaffold is used as a sensitizer loading support as well as an electron transport material, which may result in light scattering. The loss of efficiency at interfaces of the sensitizer, the mesoporous TiO2 nanoparticle films, the FTO conductive layer, and the supportive glass substrate should be considered in addition to the photoinduced electron transport properties within a cell. On the basis of optical parameters, one can obtain the internal quantum efficiency (IQE) of a solar cell, an important parameter that cannot be directly measured but must be derived from several key experiments. By integrating an optical loss model with an electrical loss model, many solar cell parameters could be characterized from electro-optical observables including reflectance, transmittance, and absorptance of the dye sensitizer, the electron injection efficiency, and the charge collection efficiency. In this work, an integrated electro-optical approach has been applied to SiPc (Pc 61) dye-sensitized solar cells for evaluating the parameters affecting the overall power conversion efficiency. The absorptance results of the Pc 61 dye-sensitized solar cell provide evidence that the adsorbed Pc 61 forms noninjection layers on TiO2 surfaces when the dye immersion time exceeds 120 min, resulting in shading light from the active layer rather than an increase in photoelectric current efficiency.