A research team led by Professor Il Jeon from the SKKU Advanced Institute of Nano Technology (SAINT) has continuously developed high-efficiency perovskite solar cells based on natural materials. Following their publication in Advanced Materials, their latest findings were published on the 9^th of this month in Advanced Energy Materials, another leading journal in the field of energy materials.

Professor Jeon's team has been at the forefront of research on bio-based and natural-material additives in the perovskite solar cell field. More recently, they explored the largely uncharted potential of cellulose-based materials (Adv. Mater. DOI: 10.1002/adma.20241032). In an attempt to replicate a prior study from China using sugar as an additive, they found that the strong hydrogen bonding (H-bonding) inherent in sugar actually hindered crystallisation. However, during experiments involving heat treatment of sugar, i.e., caramelisation, they discovered that the caramelised byproducts had a positive effect on crystal growth. This opened up a pathway for the practical utilisation of cellulose-derived natural additives.

In this new study, they used caramelised sucrose derivatives formed by thermally decomposing the natural material sucrose as an additive for perovskite solar cells.

Sucrose is a naturally derived, unrefined sugar extracted from sugarcane or sugar beet. While purified and recrystallised sucrose caused performance degradation due to its strong hydrogen bonding, the caramelised form obtained by heating at 220°C produced large amounts of humin. This humin assisted the crystallisation of the photoactive perovskite layer, reducing defects and enhancing charge transport, which ultimately led to significant improvements in performance.

As a result, the developed perovskite solar cells achieved a power conversion efficiency of 25.26%, the highest reported among solar cells using natural additives. The efficiency was officially certified at 25.07% by Daegu Technopark (DGTP). The devices also demonstrated excellent long-term stability, maintaining over 80% of their initial efficiency after 1,000 hours of continuous illumination.

Professor Jeon commented, “This is a meaningful study that establishes a precedent for using biologically derived materials in optoelectronics,” adding that “as a sustainable and eco-friendly technology, this approach holds great promise for future applications in next-generation photovoltaic and display devices.”

The research was supported by the National Research Foundation of Korea (NRF) under the Ministry of Science and ICT, and by JSPS KAKENHI. Experimental work was carried out using equipment provided by the SAINT-MBraun Application Laboratory and MBraun Co. Ltd., including a glove box system.

Paper Title (Advanced Materials): Natural and Nature-Inspired Biomaterial Additives for Metal Halide Perovskite Optoelectronics

DOI: https://doi.org/10.1002/adma.202410327

Paper Title (Advanced Energy Materials): A Sweeter Solution: Caramelized Sucrose Additives Render Eco-Friendly and High-Performance Perovskite Solar Cells

DOI: https://doi.org/10.1002/aenm.202501911

Use of caramelised sucrose derivatives formed by thermally decomposing the natural material sucrose as an additive for perovskite solar cells.