Advancing Highly Efficient and Mechanically Resilient Flexible Perovskite-Silicon Tandem Solar Cells
Authors: Zhaoyang Han, Qi Jiang
Perovskite-silicon tandem solar cells, combining high power conversion efficiency (PCE) with cost-effectiveness, are a leading direction for next-generation photovoltaics. In two-terminal tandems, a crystalline silicon (c-Si) bottom cell is series-connected with a wide-bandgap (1.65–1.7 eV) perovskite top cell, leveraging complementary spectral absorption to enhance sunlight harvesting. Rigid perovskite/c-Si tandems have achieved certified PCEs up to 34.9%, exceeding the Shockley–Queisser limit for single junctions. However, flexible perovskite-silicon tandems have lagged due to the intrinsic rigidity of c-Si, interfacial delamination under bending, and processing challenges. Recent breakthroughs in Nature report significant progress. One study by Zhang, Liu, and colleagues from Soochow University and LONGi Green Energy Technology developed a dual-buffer layer strategy using dense and loose SnOx layers formed by modulating ALD purge time. The dense layer ensures efficient charge extraction, while the loose layer acts as a cushion to relieve mechanical stress from TCO sputtering and bending. This architecture achieved a certified efficiency of 33.4% on 1 cm² and 29.8% on a wafer-scale module (~260 cm²), with a power-to-weight ratio of 1.77 W/g and bendability to 15 mm radius. These advances demonstrate the potential of flexible perovskite-silicon tandems for aerospace, wearable, and IoT applications, addressing key challenges in efficiency, flexibility, and durability.
