Modeling of interfacial and bulk charge transfer in dye-sensitized solar cells

Jiawei Gong,Zhengping Zhou,Qiquan Qiao,K Sumathy,Duc Pham

doi:10.1080/23311916.2017.1287231

Abstract

AbstractA simple, first-principles mathematical model has been developed to analyze the effect of interfacial and bulk charge transfer on the power output characteristics of dye-sensitized solar cells (DSSCs). Under steady state operating conditions, the Butler-Volmer equation and Schottky barrier model were applied to evaluate the voltage loss at counter electrode/electrolyte and TiO2/TCO interfaces, respectively. Experimental data acquired from typical DSSCs tested in our laboratory have been used to validate the theoretical J–V characteristics predicted by the present model. Compared to the conventional diffusion model, the present model fitted the experimental J–V curve more accurately at high voltages (0.65–0.8 V). Parametric studies were conducted to analyze the effect of series resistance, shunt resistance, interfacial overpotential, as well as difference between the conduction band and formal redox potentials on DSSCs’ performance. Simulated results show that a “lower-limit” of shunt resistance (1...

Highlights

During the last two decades, dye-sensitized solar cells (DSSCs) have received a considerable amount of research attention due to their low production cost, lightweight, and mechanical flexibility (Gong, Liang, & Sumathy, 2012; Gong, Sumathy, & Liang, 2012; Gong et al, 2015)
A linear relationship was observed between open-circuit voltage and photoanode temperature with a slope of −1 mV/°C, which is close to the literature reported values. This bulk and interfacial model gives an insight into the relation between physical processes in DSSCs and overall cell performance
This paper reports a first-principles mathematical model of a DSSC, based on the electrical model developed by Ferber et al Butler-Volmer equation and Schottky barrier model are integrated with the electrical model to include the interfacial voltage loss at counter electrode/electrolyte and TiO2/ transparent conducting oxide (TCO) interfaces, respectively

Summary

Introduction

During the last two decades, dye-sensitized solar cells (DSSCs) have received a considerable amount of research attention due to their low production cost, lightweight, and mechanical flexibility (Gong, Liang, & Sumathy, 2012; Gong, Sumathy, & Liang, 2012; Gong et al, 2015). A high-efficiency DSSC depends on a series of physical processes, such as good visible light harvesting, efficient charge separation, fast charge transport and low recombination rate. To further improve the device efficiency, many new materials have been synthesized and applied in DSSCs. To further improve the device efficiency, many new materials have been synthesized and applied in DSSCs These materials could generate promising outcomes, the new device structures have posed a challenge for analyzing the physical processes and operational parameters. A deep understanding of physical mechanisms which govern the device operation is essential for future development

Methods

Results

Conclusion