Interface Engineering for Organic Solar Cells: Progress toward Real-World Viability

Organic solar cells offer a promising low-cost route for renewable energy, yet single-component interfacial layers frequently cannot satisfy all practical demands simultaneously. Many standalone hole-transporting or electron-transporting materials suffer from low conductivity, abundant defects, poor film-forming capability or strict processing constraints, which hold back device efficiency, long-term stability and large-area printed manufacturing.

In a review article published in Advanced Nanocomposites, researchers from South China University of Technology and City University of Hong Kong examined composite nanocomposite interlayer strategies for organic solar cells.

The team placed reported composite interlayers into three categories: inorganic composite, organic composite, and organic-inorganic hybrid systems. “Mixing different functional components together enables synergistic effects,” explains corresponding author Prof Baobing Fan. “These composite designs can tune energy-level alignment, passivate harmful interface defects, improve thin-film quality, and optimise the morphology of the light-harvesting active layer.”

As a result, solar-cell devices obtain both higher power‑conversion efficiency and greatly improved operational durability. Many of these composite materials also show better compatibility with scalable printing techniques.

“Single‑component interfacial materials can hardly meet the full set of requirements for high photovoltaic efficiency, robust long-term operational stability and low-cost large-area fabrication all at once,” says Fan. “Each standalone material is shackled by inherent drawbacks that hinder practical deployment.”

Notably, composite strategies integrate the respective merits from diverse functional constituents, offset their intrinsic weaknesses, and deliver a viable pathway to translate promising lab-scale organic solar-cell technology into scalable, real-world industrial manufacturing.

“Our classification framework can help the community quickly navigate abundant interfacial material reports,” co-author Prof Alex K.-Y. Jen. “We hope this overview inspires more rational design of composite interlayers, accelerating the commercialization of printable organic solar cells.”

Contact the author:

Baobing Fan, National Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, P. R. China, baobifan@scut.edu.cn

Funder: 

This review was supported by the Lee Shau-Kee Chair Professor (Materials Science), APRC Grants (9380086, 9610419, 9610440, 9610492, 9610508) of the City University of Hong Kong, MHKJS Grant (MHP/054/23), TCFS grant (GHP/121/22SZ) and MRP Grant (MRP/040/21X) from the Innovation and Technology Commission of Hong Kong, Green Tech Fund (202020164) from the Environment and Ecology Bureau of Hong Kong, and GRF grants (11304424, 11307621, 11316422, 11308625) and CRS grants (CRS_CityU104/23, CRS_HKUST203/23) from the Research Grants Council of Hong Kong. This work also received partial support from City University of Hong Kong (9610739) for the UNESCO-endorsed project “Fostering Innovation for Resilience and Sustainable Transformation” within the International Decade of Sciences for Sustainable Development (2024–2033), the National Natural Science Foundation of China (No. 52573193), and the Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials.

Conflict of interest:

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

See the article:

X. Zhang, B. Fan, A. K-Y. Jen, Composite materials for interfacial engineering of organic solar cells, Advanced Nanocomposites, Volume 3, 2026, Pages 320-338, 10.1016/j.adna.2026.03.003