Flexible silicon heterojunction solar cells and modules with structured front-surface light management

Flexible silicon heterojunction (SHJ) solar cells have attracted considerable attention for their suitability in lightweight and flexible module applications owing to their bendable properties. One of the most significant challenges in producing flexible SHJ solar cells and modules is enhancing their light absorption characteristics, particularly when using thinner wafers. In this study, we implemented surface light management techniques at both the solar cell and module levels to improve light absorption. A MgF2/TCO antireflection structure was optimized for flexible SHJ solar cells, improving its external quantum efficiency (EQE) and short-circuit current density (Jsc) by 2.79% and 1.50%, respectively. Additionally, a vacuum hot-embossing process was incorporated into the front surface of flexible SHJ solar modules, incorporating various sizes of semi-elliptical anti-reflective units. This approach yielded a substantial maximum increase of 1.1% in Jsc and 1.09% in EQE for flexible modules. Furthermore, the radiation characteristics of flexible SHJ solar modules placed at different incident light angles and conducted stress analyses under bending conditions were also investigated. The findings revealed that flexibility was substantially improved with lower elastic modulus and lower thickness encapsulants. The electrical properties of the flexible modules were not deteriorated even after 1000 cycles of repeated bending tests. This study successfully addressed the bottlenecks encountered during the development of flexible crystalline silicon (c-Si) photovoltaics (PV) while highlighting the immense potential of these PVs for integrated applications.