KAIST researchers improve hybrid perovskite solar cells with enhanced infrared capture
by Riko Seibo
Tokyo, Japan (SPX) Nov 09, 2024
A team of researchers from KAIST, led by Professor Jung-Yong Lee of the School of Electrical Engineering and Professor Woojae Kim of Yonsei University’s Department of Chemistry, has announced the development of an advanced hybrid solar cell technology. This innovation enhances the capture of near-infrared light, significantly boosting power conversion efficiency and addressing key challenges in current perovskite solar cells.
Traditional lead-based perovskite solar cells are limited by their absorption spectrum, which is confined to visible light with wavelengths up to 850 nanometers. This constraint prevents them from utilizing approximately 52% of total solar energy. The new hybrid design developed by the KAIST team integrates an organic bulk heterojunction (BHJ) with perovskite, expanding absorption capabilities into the near-infrared range.
A major advancement in this technology is the introduction of a sub-nanometer dipole layer. This thin layer effectively reduces the energy barrier between the perovskite and the organic BHJ, alleviating issues such as charge accumulation.
This enhancement maximizes the near-infrared contribution and raises the current density (JSC) to 4.9 mA/cm. Consequently, the power conversion efficiency (PCE) of this hybrid solar cell has increased from 20.4% to 24.0%. The research also recorded a high internal quantum efficiency (IQE) of 78% in the near-infrared region, a significant achievement compared to previous studies.
The stability of the device is another highlight, maintaining more than 80% of its initial efficiency under extreme humidity for over 800 hours. “Through this study, we have effectively solved the charge accumulation and energy band mismatch problems faced by existing perovskite/organic hybrid solar cells,” said Professor Jung-Yong Lee. “This advancement improves power conversion efficiency and mechanical-chemical stability, overcoming optical limitations.”
The research was led by Ph.D. candidate Min-Ho Lee and Master’s candidate Min Seok Kim as co-first authors and was published in the September 30th online edition of ‘Advanced Materials’.
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