A research team led by Professor Changduk Yang from the School of Energy and Chemical Engineering at Ulsan National Institute of Science and Technology (UNIST) has achieved a major breakthrough, with findings published in Energy & Environmental Science. The study shows that camphorquinone (CQ)—a derivative of camphor, a natural extract from camphor trees—can significantly improve the quality of perovskite films in solar cells, paving the way for sustainable energy technology advancement.

Perovskite films in solar cells consist of numerous grains; larger and more ordered grains facilitate electron flow and enhance structural integrity, thereby improving efficiency and durability. Additives are commonly used during manufacturing to achieve high-quality structures, but residual additives can impair device performance.

To address this issue, the team introduced the camphor derivative CQ as an additive. CQ undergoes controlled stepwise sublimation: it initially assists uniform seed formation during the first heat treatment and gradually sublimes completely during the second heating. This controlled sublimation enables optimal perovskite film growth without leaving contaminants. First author and researcher Jeewon Park stated that CQ can precisely influence crystal growth stages at the right timing without residue, enabling the production of high-quality perovskite films.

Experimental results showed that solar cells fabricated with CQ-enhanced films achieved a power conversion efficiency (PCE) of 25.2%—an approximately 9.6% improvement over the 23.0% efficiency of control devices without additives. In maximum power point tracking (MPPT) tests simulating real-world operating conditions, these devices retained more than 90% of their initial efficiency after 1,000 hours of operation—demonstrating a lifespan more than twice that of comparable control devices.

Professor Changduk Yang remarked that using environmentally friendly, natural materials to solve the stability issues of perovskite solar cells not only advances sustainable energy technology but also paves the way for more durable and cost-effective solar solutions. This breakthrough is expected to extend solar cell lifespan, increase efficiency, simplify manufacturing processes, and reduce production costs.