2D Composite Materials for Electrodes in Dye-Sensitized Solar Cells─An Overview

Dye-sensitized solar cells (DSSCs) are anticipated to become economical, efficient, and commercially viable due to their simple fabrication, environmental friendliness, low-light performance, and flexibility for product integration. However, inherent voltage loss during the sensitizing dye regeneration process, uneven titanium layer deposition, electrolyte filling, and electrical interconnections contribute to the lower efficiency of DSSCs compared to conventional silicon solar cells. Researchers have focused on optimizing material and structural properties to address these issues, achieving record-setting efficiencies of up to 14%. Recently, incorporating 2D materials, such as graphene and transition metal carbides or nitrides (MXenes), has been studied to improve DSSC performance and stability. 2D materials can enhance the photoanode's diffuse reflectance, increasing light utilization efficiency. This review provides an overview of recent progress in DSSC research toward developing new materials (2D) for electrodes, focusing on applying 2D composite materials. We discuss how each of these materials has been utilized as hole-transporting layers or as dopants in electrodes to improve the photovoltaic performance and long-term stability of DSSCs. Furthermore, we outline the features that must be optimized for the highest efficiency in DSSCs and provide a perspective on future directions in DSSC research.