Chinese researchers achieve milestone breakthrough in flexible solar cells

BEIJING -- Chinese researchers have systematically resolved key challenges in efficiency and stability for flexible tandem solar cells, achieving a milestone breakthrough in silicon-based flexible photovoltaics, China Science Daily reported on Monday.

Led by researchers from Soochow University, the study was published in the journal Nature on Thursday last week.

The commercialization of flexible crystalline silicon/perovskite tandem solar cells faces two major bottlenecks: their efficiency still lags behind that of rigid devices, and their interfaces are susceptible to delamination and degradation under repeated bending or harsh conditions.

To address these challenges, the research team designed a dual-layer buffer featuring a "loose-tight" structure, which synergistically dissipates mechanical stress while preserving efficient charge transport at the nanoscale.

They also developed a method for preparing hydrogen-doped indium-cerium oxide films via reactive plasma deposition, which minimizes interfacial sputtering damage and optimizes energy level alignment.

These advancements have allowed the team to realize a certified conversion efficiency of 33.6 percent on an ultra-thin 60 micrometers silicon substrate, setting a new efficiency record for flexible tandem cells.

Moreover, a large-area device (261 square centimeters, standard wafer size) achieved an efficiency of 29.8 percent, also a world record for flexible tandem cells of that scale. The devices also demonstrated outstanding mechanical durability, retaining 97 percent of their initial efficiency after 43,000 extreme bending cycles.

This work establishes a solid scientific and technical foundation for the large-scale application of flexible photovoltaics and opens up new opportunities for the silicon-based solar industry.