2D materials and additives: a dual approach to high-performance tin perovskite solar cells

Tin halide perovskite solar cells (THPSCs) are an eco-friendly alternative to lead halide perovskite solar cells (LHPSCs). However, defect formation hinders their commercialization. Specifically, the oxidation of Sn²⁺ to Sn⁴⁺ generates defects, which increase background current due to charge recombination and consequently degrade device performance. This review explores the use of 2D materials and additives to enhance the performance and stability of THPSCs. 2D materials improve charge transport, passivate defects, induce vertical alignment, and enhance structural stability against moisture. Additives optimize film morphology and interface properties by promoting grain growth and reducing defect density. These approaches increase the power conversion efficiency (PCE) of THPSCs by up to 15%, demonstrating their commercial potential. The synergistic effects of 2D materials and additives are analyzed, and critical strategies for their combined utilization are suggested to develop high-efficiency and stable THPSCs.