Researchers suggest that fluoroethylamine engineering or effective passivation can improve the power conversion efficiency of perovskite solar cells.
Perovskite solar cells have gained much attention due to high power conversion efficiency. In perovskite solar cells, the layer of perovskite film determines the performance and stability of the device.
In the manufacturing process of perovskite solar cells (PSCs), many defects will be introduced at the grain boundaries and interfaces, which will act as non-radiative recombination centers and seriously damage the performance and stability of PSCs.
A group of researchers led by Prof. Liu Shengzhong from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) and his cooperators used fluoroethylamine (FEA) cations into the perovskite film to form highly efficient and stable PSCs.
The researchers found that perovskite film with FEA passivation improved photoluminescence (PL) intensity, prolonged carrier-lifetime, suppressed nonradiative recombination, enlarged grain size and hydrophobicity, and as a result, delivered high device performances.
Researchers indicate that different amounts of fluorine additives presented a gradient distribution in the film. The device employing 2-fluoroethylamine (1FEA) achieved an efficiency of 23.40%, while the device employing 2, 2, 2-trifluoroethylamine (3FEA) showed the best environmental stability, maintaining 87% of their initial efficiencies after 1200 h.
According to Prof. Liu, their work paves a new way to fabricate high-efficiency and stable PSCs.
The research has been published in the journal Advanced Energy Materials.