Herbert Kroemer, recipient of the 2000 Nobel Prize in Physics, famously said: "The interface is the device." This insight is especially true for perovskite solar cells, where poorly controlled interfaces often lead to complex fabrication, inefficient charge transport, and severe nonradiative losses.
To address this challenge, the research team developed a "double molecular bridge" strategy using a newly designed functional additive, 4-F-PEAFa.
- Bridge 1: At the perovskite/hole transport layer interface, the molecule forms a bridge to accelerate hole extraction.
- Bridge 2: At the perovskite/electron transport layer interface, it builds another bridge to facilitate electron transport.
Uniquely, both bridges originate from the same multifunctional molecule, making the strategy both elegant and efficient.
Illustration: Double molecular bridges enable charge transport in perovskite solar cells
Key Results:
- Record Efficiency: Devices achieved a champion efficiency of 26%, with a certified efficiency of 25.6% and a certified fill factor up to 0.88—the highest reported for inverted perovskite solar cells to date.
- Outstanding Stability: Unencapsulated devices maintained over 90% of initial efficiency after 2000 hours at 85°C or 1000 hours under continuous operation, addressing critical barriers to commercialization.
This breakthrough not only confirms Kroemer's prediction—"the interface is the device"—but also opens a new avenue for interface engineering in perovskite photovoltaics: let molecules "build bridges" so charges can "fly."
Authors and Affiliations:
The work was led by Qing Lian (SUSTech), Lina Wang (Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, formerly SUSTech), Guoliang Wang (University of Sydney), and Guojun Mi (SUSTech) as co-first authors. Co-corresponding authors include Bowei Li (Shanghai Jiao Tong University), Wei Zhang (University of Surrey), Guangfu Luo (SUSTech), Henry J. Snaith (University of Oxford), and Chun Cheng (SUSTech).
