Effect of Different Bromine Sources on the Dual Cation Mixed Halide Perovskite Solar Cells

article
Recent research has shown that perovskite solar cells with a mixed dual A-cation have much better structural stability without loss of efficiency than single cation devices. Mixed cation perovskites create a lot of questions about the salts being used for the formation of the best-quality layer. Here, we have investigated three sources of bromide in the perovskite absorption layer, using lead bromide (PbBr2), formamidinium bromide (FABr), and cesium bromide (CsBr). The experimental results have shown better performance for FABr and CsBr sources of bromide in comparison to the regularly used PbBr2. This effect has been explained with the complex species present in the not-annealed perovskite films which changes the defect states during the crystallization of the absorber layer. It has been found with numerical simulations that the observed phenomenon directly impacts the rates of the trap-assisted recombination. The results of this study are one more step forward in understanding the physics behind the crystallization process which is crucial in further improvement of the perovskite solar cells.
TNO Identifier
884352
ISSN
25740962
Source
ACS Applied Energy Materials, 3(9), pp. 8285-8294.
Publisher
ACS
Pages
8285-8294