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Updated: Sep 3, 2025
Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells
Published on: March 19, 2017
Visualization of Ion Migration in an Inorganic Mixed Halide Perovskite by One-Photon and Multiphoton Absorption:
Po-Kai Kung1, Kuang-I Lin2, Chun-Sheng Wu1
1Department of Photonics, National Cheng Kung University, Tainan 701, Taiwan.
Abstract:
In this work, we present the ion migration of CsPbIBr2 under illumination and impede it by incorporating the large cations of guanidinium (GA). A series of "probe-set-probe" operations are applied to assess the photoluminescence (PL) behavior spectrally and spatially, which is correlated to the ion migration-induced phase separation, of CsPbIBr2 and GACs1-PbIBr2 perovskites. The local lattice distortion introduced by GA could reduce the strain gradient in GACs1-PbIBr2 to inhibit the ion migration, leading to a stable PL spectrum and enhanced device stability under light stimulation. A solar cell with an optimized stoichiometric composition of GA0.1Cs0.9PbIBr2 delivers comparable photovoltaic performance and improved stability compared to those of CsPbIBr2-based perovskite solar cells, retaining 80% of its initial power conversion efficiency after being continuously bathed in light for 8 h under ambient conditions without encapsulation, while the CsPbIBr2 counterpart shows an efficiency that is <30% of its initial value under the same test condition.
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