Insights and future perspectives for constructing efficient electron pathways in photoanodes of QDSSCs

Abstract

Abstract Quantum dot sensitized solar cells (QDSSCs) can capably align with other emerging photovoltaic technologies, because of their ability to generate multiple excitons, availability of dynamic absorption ranges, and power conversion efficiency approaching 15% and beyond. Although the light-harvesting ability of these QDSSCs has increased dramatically, with EQE reaching up to 100%, charge carrier recombination has remained a major concern in retarding device performance and stability. The loss of charges within the semiconductor and across the photoanode interfaces has, to a large extent hindered device efficiency. As a result, it is critical to investigate an efficient and robust method of controlling charge recombination processes through thoughtful design. In this review, we summarize and offer insights into the most recent innovations with respect to design and construction of electron transport materials, with a focus on reducing recombination pathways via the dimensional nanostructures, carbon materials, and dopants; these being the three main strategies that have received much attention in recent years. The review also discusses and analyzes the solutions proposed by various researchers to overcome the challenges that restrict the electron transport in photoanodes of QDSSCs. Finally, the perspectives provide a) insights into choosing suitable materials, techniques and methods and also b) identifies and indicates potential areas that need attention or has scope for development.