Researchers from Seoul’s Hanyang University and China’s Nankai University have developed an electron transport layer (ETL)–based cesium lead iodide perovskite quantum dot solar cell with a record power conversion efficiency (PCE) of 12.7%.

The scientists claim that the solar cell managed to maintain 94% of the initial PCE after 500 bending tests.

Despite being a critical component in perovskite quantum dot (PQD) solar cells, ETL has been known to impact their photovoltaic performance and stability significantly.

However, the recently published study in Nature offers an innovative approach to enhance the performance and stability of flexible CsPbI3-PQD (cesium lead iodide perovskite quantum dot) solar cells using UV-sintered tin oxide (SnO₂) as the electron transport layer. This approach bypasses the need for high-temperature annealing, making it suitable for use with polymer substrates in flexible solar cells.

The team also found that the systematically designed enhanced photovoltaic performance and mechanical stability of flexible optoelectronic devices. A flexible solar cell where CsPbI3-PQD acted as a light absorber achieved the highest PCE among flexible quantum dot cells.

The research also introduced a room-temperature process for preparing the SnO2 ETL, which utilized UV irradiation to remove organic ligands from the SnO2 nanocrystals. This further enabled the creation of high-quality thin films at temperatures compatible with flexible substrates.

The team found that these cells also offer enhanced mechanical stability as opposed to bulky perovskite films due to their nanoscale grain boundaries and soft surface ligands. This helped underscore their potential as flexible device components, increasing their commercialization in the solar energy sector.

The doping method also allowed researchers to reduce the energy mismatch between CsPbI3-PQD and the ETL, which holds great promise in reducing potential losses and improving the solar cell’s efficiency.

Earlier this month, researchers from the National University of Singapore achieved a record energy conversion efficiency of 27.1% by developing a new triple-junction solar cell.

It was also found that by engineering the nanoscale structure of perovskite devices, researchers were able to make perovskite solar panels more efficient and sturdier over longer periods.