Chinese researchers have developed a molecular additive that reduces defects in perovskite solar cells, enabling a power conversion efficiency of 27.39%. The approach was also used in bifacial mini-modules with efficiencies above 22% and 99.6% power retention after more than 5,000 hours of continuous operation.
A research group in China has fabricated a perovskite solar cell using a new molecular design approach aimed at reducing defects in the perovskite film and increasing device efficiency and stability.
“Rapid film crystallization can generate subtle defects that become concentrated at surfaces, grain boundaries, and buried interfaces,” the research’s lead author, Cong Chen, told pv magazine. “Although molecular additives can effectively mitigate these imperfections, their design requires a careful balance: strong interactions favor defect passivation, but excessive molecular packing or the formation of insulating interfacial layers can hinder charge transport.”
“Additive engineering offers a practical strategy to address these challenges by regulating crystallization while simultaneously passivating electronic defects,” he went on to say. “However, effective additives must balance strong defect binding with unhindered charge transport while ideally providing additional protection against environmental stress.”
