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We report on the optical properties of a CsPbBr3polycrystalline thin film on a single grain level. A sample composed of isolated nanocrystals (NCs) mimicking the properties of the polycrystalline thin film grains that can be individually probed by photoluminescence spectroscopy was prepared. These NCs were analyzed using correlative microscopy allowing the examination of structural, chemical, and optical properties from identical sites. Our results show that the stoichiometry of the CsPbBr3NCs is uniform and independent of the NCs’ morphology. The photoluminescence (PL) peak emission wavelength is slightly dependent on the dimensions of NCs, with a blue shift up to 9 nm for the smallest analyzed NCs. The magnitude of the blueshift is smaller than the emission line width, thus detectable only by high-resolution PL mapping. By comparing the emission energies obtained from the experiment and a rigorous effective mass model, we can fully attribute the observed variations to the size-dependent quantum confinement effect.

A Hermite finite-elements approach with adaptive mesh refinement for the solution of a set of second-order ordinary differential equations is described. The main advantage of the method is its usability for stiff equations with boundary conditions. For cases where exponentially growing solutions can exist, the method overcomes the common problems of initial value solvers. The method was successfully used for the full-wave solution of wave propagation in inhomogeneous plasma where the mode conversion process between ordinary, extraordinary and electron Bernstein waves occurs.