Quantification of Ionic Diffusion in Lead Halide Perovskite Single Crystals
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
Materials Science and Engineering Program
KAUST Catalysis Center (KCC)
MetadataShow full item record
AbstractLead halide perovskites are mixed electronic/ionic semiconductors that have recently revolutionized the photovoltaics field. The physical characterization of the ionic conductivity has been rather elusive due to the highly intermixing of ionic and electronic current. In this work the synthesis of low defect density monocrystalline MAPbBr3 (MA=Methyl ammonium) solar cells free of hole transport layer (HTL) suppresses the effect of electronic current. Impedance spectroscopy reveals the characteristic signature of ionic diffusion (the Warburg element and transmission line equivalent circuit) and ion accumulation at the MAPbBr3/Au interface. Diffusion coefficients are calculated based on a good correlation between thickness of MAPbBr3 and characteristic diffusion transition frequency. In addition, reactive external interfaces are studied by comparison of polycrystalline MAPbBr3 devices prepared either with or without a HTL. The low frequency response in IS measurements is correlated with the chemical reactivity of moving ions with the external interfaces and diffusion into the HTL.
CitationPeng W, Aranda C, Bakr OM, Garcia-Belmonte G, Bisquert J, et al. (2018) Quantification of Ionic Diffusion in Lead Halide Perovskite Single Crystals. ACS Energy Letters. Available: http://dx.doi.org/10.1021/acsenergylett.8b00641.
SponsorsWe acknowledge funding from Spanish Ministerio de Economía y Competitividad of Spain under Project MAT2016-76892-C3-1-R and for a Ramón y Cajal Fellowship (RYC-2014-16809). OMB and WP acknowledge the financial support of KAUST.
PublisherAmerican Chemical Society (ACS)
JournalACS Energy Letters