Fig. 3: Scalable luminescent patterns and anisotropic enhanced PL on oriented MAPbBr3 wafers.
a Open-aperture Z-scan measurements performed on the differently oriented MAPbBr3 single-crystal wafers. The fitting equation of the the theoretical model is: TTPA = [1 + (n-1) αn Leff (I0/(1 + (z/z0)2))(n-1)]-1/(n−1), Leff = (1-e-αL)/α, where αn represents the effective multiphoton absorption coefficient, I0 is the laser intensity, z0 is the Rayleigh length, Leff is the effective length of the sample, α is the linear absorption coefficient, and L is the actual length of the sample. b Schematic illustration of the femtosecond laser two-photon processing measurement performed on oriented MAPbBr3 crystal. The insets are the fluorescence and height profile images of LSCM. c Micro-PL spectra of three MAPbBr3 wafers before and after processing. d Micro-Raman spectra of (001) wafer before and after processing. The inset is the scanning electron microscope (SEM) image of processed MAPbBr3. e The optical microscopy (OM) and FM images of femtosecond laser-processed scalable patterns on three MAPbBr3 wafers. The processing parameters are [laser power: 5 mW, defocus: 470 μm and scanning speed: 0.1 mm s−1]. f The microstructures (SEM) induced by femtosecond laser of the (100), (110), and (111) wafers.
