Interfacial Charge-Transfer Loss in Dye-Sensitized Solar Cells

Abstract

Interfacial charge-transfer loss factors (CTLFs) of dye-sensitized solar cells (DSCs) were studied using a thermionic emission-diffusion theory and electrochemical impedance spectroscopy (EIS). It is found that the subsidiary CTLFs can be quantified including a native charge-transfer loss at the TiO2/electrolyte interface in DSC devices. The obtained CTLFs as a probability parameter a were identified as almost matching to dominant resistance-capacitance (RC) time constants obtained from the EIS and its numerical calculation. The quantified CILFs based on a detailed physical model of quantum-mechanical tunneling and reflection of charge carriers can explain a degradation of open-circuit voltage in DSC devices.