Zheng Likai, a PhD graduate of Nanjing University of Aeronautics and Astronautics (NUAA), recently published a first-authored article in Science titled Strain-Induced Rubidium Incorporation Into Wide-Bandgap Perovskites Reduces Photovoltage Loss.
According to the article, A-site cation mixing can enhance the photovoltaic performance of a wide-bandgap (WBG) perovskite, but rubidium (Rb) cation mixing generally forms a nonperovskite phase. The research group reports that lattice strain locks Rb ions into the α-phase of the lattice of a triple-halide WBG perovskite, preventing phase segregation into a nonperovskite Rb-cesium–rich phase.
This process cooperates with chloride accommodation and promotes halide homogenization across the entire film volume. The resulting 1.67–electron volt WBG perovskite exhibits photoluminescence quantum yields exceeding 14 percent under 1-sun-equivalent irradiation, corresponding to a quasi–Fermi level splitting of ~1.34 electron volts.
A WBG perovskite solar cell with an open-circuit voltage (VOC) of 1.30 volts was prepared, corresponding to 93.5 percent of the radiative VOC limit and representing the lowest photovoltage loss relative to the theoretical limit observed in WBG perovskites.
Huang Bin, a PhD candidate from NUAA’s low-carbon aviation power and green energy innovation team, also contributed to this research, with academician Xuan Yimin serving as a co-corresponding author.
Doctor Zheng earned his PhD in power engineering and engineering thermophysics from NUAA in September 2022 and subsequently conducted postdoctoral research at the École Polytechnique Fédérale de Lausanne (EPFL), Switzerland, joining the research group of Michael Grätzel, professor of Physical Chemistry at the EPFL.
The performance and stability of wide-bandgap perovskite solar cells. [Photo/en.nuaa.edu.cn]
