We are using optical spectroscopy and microscopy to characterize the structural and photophysical properties of inorganic nanomaterials with the goal of optimizing these materials for use in energy capture and conversion devices. A series of five methylammonium lead halide perovskites (CH3NH3PbBr3-xIx) was synthesized with varying iodide and bromide anion loading. The luminescence can be tuned across the visible to near infrared (500 nm and 770 nm) by varying the halide loading. Single particle luminescence of the 2 to 32-nm nanocrystals was used to study the time-correlated luminescence of the methylammonium lead halide perovskites. We have demonstrated that the CH3NH3PbBr3 and CH3NH3PbI3 nanoparticles exhibit no luminescence intermittency. Between 4 to 26% of the mixed halide perovskite nanocrystals exhibited luminescence intermittency. The data suggest that surface trapping and detrapping are responsible for the intermittent luminescence. The luminescence intermittency of 5 to 10-nm cesium lead halide perovskites (CsPbX3, X=Cl, Br, I) will also be discussed. Finally, Raman microscopy studies of cesium lead halide perovskite photostability and thermostabilty will be presented. The perovskite nanocrystals will be useful in a wide-range of microscopy and energy applications such as single particle tracking and for producing efficient energy capture and conversion devices.

Single particle luminescence and Raman spectroscopy analyses of lead halide perovskite nanocrystals

255th National Meeting (2018)

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