Integrated Perovskite/Silicon Tandems for Unassisted Water Splitting and CO2-to-Liquid Fuel Conversion

Integrated Perovskite/Silicon Tandems for Unassisted Water Splitting and CO2-to-Liquid Fuel Conversion

ACS Energy Letters

10.1021/acsenergylett.6c01379

https://doi.org/10.1021/acsenergylett.6c01379

Bilawal Khan, M. Bilal Faheem, Md. Samim Hassan, Maxime Babics, Karthik Peramaiah, Chengda Ge, Hongyin Xia, Jiang Liu, Madan Saud, Yuk-Tong Cheng, Andrey L. Rogach, Quinn Qiao, Kuo-Wei Huang, Stefaan De Wolf, Jr-Hau He

photoelectrochemical system

12 June 2026

Khan, B., Faheem, M. B., Hassan, Md. S., Babics, M., Peramaiah, K., Ge, C., Xia, H., Liu, J., Saud, M., Cheng, Y.-T., Rogach, A. L., Qiao, Q., Huang, K.-W., De Wolf, S., & He, J.-H. (2026). Integrated Perovskite/Silicon Tandems for Unassisted Water Splitting and CO2-to-Liquid Fuel Conversion. ACS Energy Letters. https://doi.org/10.1021/acsenergylett.6c01379

Integrated photoelectrochemical systems offer a promising pathway to produce value-added fuels from sunlight and abundant reagents. However, practical implementation remains challenging due to insufficient operating photovoltage, charge-carrier losses at the electrode–catalyst interface, and high catalytic overpotentials. Here, we fabricate a perovskite/silicon photoanode that combines a wide-bandgap metal-halide perovskite top junction with a double-textured crystalline silicon bottom junction to increase operating photovoltage. To minimize charge-transfer losses and promote catalyst adhesion, we integrate a photoanode with a graphite layer and further functionalize it with a low-overpotential Co-doped IrRu catalyst. The integrated photoanode achieves an open-circuit voltage of 1.86 V and a current density of 19 mA cm−2 at +1.23 VRHE. During unassisted two-electrode water splitting, the system achieves a solar-to-hydrogen efficiency of 16.06% and operates for 157 h. Extending to CO2-to-formate conversion, the two-electrode device reaches an applied-bias photon-to-current efficiency of 10.08% over 60 h. Our study highlights the potential of integrated photoelectrochemical systems for efficient solar-to-fuel conversion.

Attribution 4.0 International (CC BY 4.0)

J.-H.H. acknowledges funding from City University of Hong Kong (9380107).

https://oar.a-star.edu.sg/communities-collections/articles/23450

2380-8195
2380-8195

Institute of Sustainability for Chemicals, Energy and Environment

https://doi.org/10.1021/acsenergylett.6c01379