Dye–Sensitized Solar Cells: An Overview

Abstract

Today, a particular interest in the development of alternative energy sources arises, especially motivated by the need of decreasing the dependency on fossil‐fuel resources, and also for the prospect of reducing CO 2 emissions. An attractive strategy to overcome the present energy problem is using renewable energy sources, such as the solar radiation, for producing clean energy. This article describes the main features of dye‐sensitized solar cells (DSCs), explaining their structure and working principles, and highlighting the characteristics of the main materials for high‐performance DSCs. After this brief discussion, the fundamentals behind electrochemical impedance spectroscopy (EIS) are described in order to allow the interpretation of the charge‐transfer kinetics of the different phenomena occurring in a DSC under operation. A phenomenological model addressing the major charge‐transfer mechanisms and energy losses is presented for a better understanding of the factors that limit the performance of DSCs. While a steady‐state approach allows the construction of the current‐voltage characteristics of the cell, the transient approach model is an invaluable tool to relate the phenomenological behavior with certain dynamic techniques, such as EIS.

Recent Advances in Dye Sensitized Solar Cells

“…Therefore, grapheme and conductive polymers have also been used as alternative materials for counter electrode [1]. But their electrical efficiencies were very low when compared to the Pt catalyst.…”

“…The world energy demand is continuously increasing and the world power consumption, which is 13 terawatts (TW) currently, is expected to reach about 23 TW in 2050 [1]. Fossil fuels, which are depleting rapidly, meet 80% of the energy requirement of the whole world [2].…”

“…The structure and working principle of DSSC is shown in Figure 1. A charge separation process in a DSSC consists of the following steps [1].…”