Perovskite Tandem Solar Cell Sets New Benchmark for Efficiency
- ritambhara516
- Jun 27
- 3 min read
Assistant Professor Hou Yi (middle), Dr Jia Zhenrong (left), Mr Guo Xiao (right) and their team achieved a record power conversion efficiency of 26.4% with a new perovskite-organic tandem cell design (held by Asst Prof Hou).
Researchers at CDE have developed a perovskite–organic tandem solar cell that has achieved a certified world-record power conversion efficiency of 26.4% over a one cm² active area.
This marks the highest efficiency ever recorded for this type of device and was made possible by the introduction of a newly engineered narrow-bandgap organic absorber. This innovation greatly improves near-infrared (NIR) photon absorption—an area that has long posed challenges in thin-film tandem solar cell performance.
The breakthrough was led by Assistant Professor Hou Yi, a Presidential Young Professor in the Department of Chemical and Biomolecular Engineering at CDE, and head of the Perovskite-based Multijunction Solar Cells Group at the Solar Energy Research Institute of Singapore (SERIS), part of NUS. The team’s findings were published in the journal Nature on 25 June 2025.
Perovskite and organic semiconductors both possess highly tunable bandgaps, allowing tandem solar cells to achieve near-maximum theoretical efficiencies.
“As they are lightweight and flexible, perovskite–organic tandem solar cells are particularly well-suited for powering devices directly—such as drones, wearable tech, smart textiles, and other AI-integrated systems,” explained Assistant Professor Hou.
Despite this potential, progress has been hindered by the lack of efficient near-infrared (NIR) thin-film absorbers, which are essential for capturing sunlight in the NIR spectrum and boosting the overall performance of tandem cells. This limitation has caused perovskite-organic tandem designs to fall behind other competing technologies.
Harnessing the near-infrared
To address this challenge, Assistant Professor Hou and his team engineered an asymmetric organic acceptor featuring an extended conjugation structure. This design allows for deeper absorption in the near-infrared (NIR) range while preserving a strong driving force for effective charge separation and encouraging well-ordered molecular packing.
Through ultrafast spectroscopy and device physics studies, the team confirmed that this approach enables efficient collection of free charge carriers with minimal energy loss.
Building on the strong performance of the organic subcell, the research team stacked it beneath a high-efficiency perovskite top cell, using a transparent conducting oxide (TCO)-based interconnector to join the layers.
The resulting tandem solar cell achieved a power conversion efficiency of 27.5% on 0.05 cm² samples and 26.7% on 1 cm² devices, with an independently verified efficiency of 26.4%.
These results represent the highest certified efficiency to date for perovskite–organic, perovskite–CIGS, and single-junction perovskite solar cells of similar size.
“With efficiency levels approaching 30%, these flexible films are well-suited for roll-to-roll manufacturing and easy integration onto curved surfaces or fabrics — enabling innovations like solar-powered health patches that run onboard sensors, or smart textiles that track biometrics without bulky batteries,” said Assistant Professor Hou.
The team’s next research phase will focus on improving real-world durability and scaling up to pilot-line manufacturing — key steps toward commercializing this flexible, high-performance solar technology.
To address this challenge, Assistant Professor Hou and his team engineered an asymmetric organic acceptor featuring an extended conjugation structure. This design allows for deeper absorption in the near-infrared (NIR) range while preserving a strong driving force for effective charge separation and encouraging well-ordered molecular packing.
Through ultrafast spectroscopy and device physics studies, the team confirmed that this approach enables efficient collection of free charge carriers with minimal energy loss.
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