engleski

Effects of ambient exposure on photoluminescence of Dion-Jacobson tin-based halide perovskite

Tin-based halide perovskite materials are of interest for light-emitting applications due to their broad yellow emission, but they are known to exhibit inferior stability compared to the lead- based perovskites due to tendency of Sn2+ to be readily oxidized. Here we investigated the ambient stability of a Dion-Jacobson tin bromide perovskite. We found that the optical properties of the samples were more significantly affected by the moisture rather than the ratio of Sn2+/Sn4+. The exposure to humidity resulted in changes in the ratio of 2D HDASnBr4 and hydrated 1D HDA3SnBr8 phases, with initial increase (up to ~40 h) in luminescence attributed to increasing fraction of hydrated 1D phase which contributes to self- trapped exciton emission. With further exposure to humidity, the material starts to degrade resulting in reduced luminescence after ~40 h. The use of additives for the suppression of oxidation of Sn2+, namely SnCl2 and tetraethyl orthosilicate (TEOS), results in prolonging the lifetime of the samples (>260 h for thin films with additives, compared to 180 h for thin films without additives). However, the persistence of luminescence with increased time of ambient exposure in samples prepared with additives can be attributed to the changes in the evolution of phase composition (rati-os of 2D and hydrated 1D phases) over time rather than suppressing the oxidation of Sn2+.

Dion-Jacobson ; tin-based halide perovskite

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