CDE and SERIS set 26.4% efficiency record for organic tandem cell

Researchers from the College of Design and Engineering (CDE) and the Solar Energy Research Institute of Singapore (SERIS)demonstrated a perovskite–organic tandem solar cell. It achieved a certified world-record efficiency of 26.4 per cent over a 1 cm² area. The breakthrough makes it the highest-performing device of its kind to date. The performance is driven by a newly designed narrow-bandgap organic absorber. This significantly enhances near-infrared (NIR) photon harvesting. NIR harvesting has been a long-standing bottleneck in thin-film tandem solar cells. The team was led by Assistant Professor Hou Yi. They developed an asymmetric organic acceptor with an extended conjugation structure. This enables deep NIR absorption while maintaining efficient charge separation. The tandem cell achieved 27.5 per cent efficiency on 0.05 cm² samples. It also reached 26.7 per cent efficiency on 1 cm² devices.