Cargando…

Impact of Orientational Glass Formation and Local Strain on Photo-Induced Halide Segregation in Hybrid Metal-Halide Perovskites

[Image: see text] Band gap tuning of hybrid metal–halide perovskites by halide substitution holds promise for tailored light absorption in tandem solar cells and emission in light-emitting diodes. However, the impact of halide substitution on the crystal structure and the fundamental mechanism of ph...

Descripción completa

Detalles Bibliográficos
Autores principales: van de Goor, Tim W. J., Liu, Yun, Feldmann, Sascha, Bourelle, Sean A., Neumann, Timo, Winkler, Thomas, Kelly, Nicola D., Liu, Cheng, Jones, Michael A., Emge, Steffen P., Friend, Richard H., Monserrat, Bartomeu, Deschler, Felix, Dutton, Siân E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2021
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8287560/
https://www.ncbi.nlm.nih.gov/pubmed/34295448
http://dx.doi.org/10.1021/acs.jpcc.1c03169
Descripción
Sumario:[Image: see text] Band gap tuning of hybrid metal–halide perovskites by halide substitution holds promise for tailored light absorption in tandem solar cells and emission in light-emitting diodes. However, the impact of halide substitution on the crystal structure and the fundamental mechanism of photo-induced halide segregation remain open questions. Here, using a combination of temperature-dependent X-ray diffraction and calorimetry measurements, we report the emergence of a disorder- and frustration-driven orientational glass for a wide range of compositions in CH(3)NH(3)Pb(Cl(x)Br(1–x))(3). Using temperature-dependent photoluminescence measurements, we find a correlation between halide segregation under illumination and local strains from the orientational glass. We observe no glassy behavior in CsPb(Cl(x)Br(1–x))(3), highlighting the importance of the A-site cation for the structure and optoelectronic properties. Using first-principles calculations, we identify the local preferential alignment of the organic cations as the glass formation mechanism. Our findings rationalize the superior photostability of mixed-cation metal–halide perovskites and provide guidelines for further stabilization strategies.