Kubicki, DJProchowicz, DHofstetter, AZakeeruddin, SMGratzel, MEmsley, L2018-11-082018-11-082018-11-08201810.1021/jacs.8b03191https://infoscience.epfl.ch/handle/20.500.14299/150763WOS:000435525500027Phase Segregation in Potassium-Doped Lead Halide Perovskites from K-39 Solid-State NMR at 21.1 Ttext::journal::journal article::research article