Giant magneto field effect in up-conversion amplified spontaneous emission via spatially extended states in organic-inorganic hybrid perovskites

Up-conversion lasing actions are normally difficult to realize in light-emitting materials due small multi-photon absorption cross section and fast dephasing of excited states during excitation. This paper reports an easily accessible up-conversion amplified spontaneous emission (ASE) organic-inorganic hybrid perovskites (MAPbBr3) films by optically exciting broad gap with sub-bandgap laser The was optimized adjusting the grain sizes MAPbBr3 films. At low pumping intensities, directly leads 2-photon, 3-photon, 4-photon emission, revealing a large optical excitation occurring such perovskite moderate intensity (1.19 mJ/cm2) 700 nm excitation, significant spectral narrowing phenomenon observed full width at half maximum (FWHM) decreasing from 18 4 peak wavelength 550 nm, simultaneously nonlinear increase on intensity, showing ASE realized threshold fluence. More interestingly, demonstrated giant magnetic field effect, leading magneto-ASE reaching 120%. In contrast, photoluminescence (PL) showed negligible effect (< 1%). observation provides evidence indicate that responsible for essentially formed as spatially extended states. angular dependent spectrum results further verify existence which polarized develop coherent in-phase interaction. Clearly, using presents new approach perovskites.