Recent Progress and Future Prospects for Light Management of All-Perovskite Tandem Solar Cells

Developing tandem solar cells is an excellent strategy to break through the Shockley-Queisser limit for single-junction solar cells. All-perovskite tandem solar cells (all-PTSCs) are considered to have great potential by virtue of their advantages of low-cost and low-temperature fabrication. However, complicated light distribution and potential loss of incident light are two issues that hinder the development of all-PTSCs. In this review, the recent progress in light management of two-terminal (2T) and four-terminal (4T) all-PTSCs is summarized. The authors discuss the problems with wide-bandgap and narrow-bandgap sub-cells and optimization strategies for efficient light management of tandem solar cells. Then, main light losses are analyzed, such as parasitic absorption, reflection, and thermal relaxation. Current mismatching is a critical condition that can affect the practical application of 2T tandem solar cells. The authors discuss how the thickness and bandgap of the absorber layer, interference, back reflections, and light distribution influence on light losses in devices and ultimately impact current matching. Also, the impact of light management on the performance of all-PTSCs is comprehensively reviewed. Finally, key issues and the prospects for the future development of all-PTSCs are outlined.