Low Inhomogeneous Broadening of Excitonic Resonance in MAPbBr₃ Single Crystals

Abstract

We present optical study of MAPbBr 3 single crystals grown from solution by inverse temperature crystallization method. Photoluminescence temperature dependence of narrow and isolated exciton resonance showed encouragingly low inhomogeneous broadening Γ ≈ 0.5 meV, which is comparable to those of MBE-grown III-V heterostructures, indicating high quality of the solution-grown perovskite. Excitonic origin of the resonance was proved by its superlinear pump intensity dependence in contrast to the linear behavior of the defect-assisted recombination bands. In addition, for the first time phonon replicas were resolved in MAPbBr 3 photoluminescence spectra and attributed to the known lattice vibrational modes by comparison with Raman scattering spectra.

Amplified Spontaneous Emission and Random Lasing in MAPbBr3 Halide Perovskite Single Crystals

“…The PL spectra has a narrow bound exciton peak with a Stokes‐shift of around 5 meV, and a defect‐related broad PL at energies below this peak. [ 45 ] For the PL pumping femtosecond UV laser pulses with a 80 MHz repetition rate were used.…”

Continuous-wave lasing from perovskites embedded microcavities

“…Thus, it is reasonable to fit the FWHM with a linear function. The estimated values of 0 and are 3.94 meV and 0.08 meV/K, respectively, which are agreed well with the previous report [119,122]. Such a low value of inhomogeneous broadening suggests the excellent optical quality of the singlecrystalline MAPbBr3 nanoplates with low-density defects.…”

“…The corresponding coupling strengths between exciton and phonon are and , and stands for the energy of the LO phonons. At temperatures below 80K, the broadening mechanism is governed by the coupling to an acoustic phonon, while the contribution of optical phonon is negligible [122,124]. Thus, it is reasonable to fit the FWHM with a linear function.…”

Efficient third harmonic generation from FAPbBr3 perovskite nanocrystals

“…Halide perovskites offer an interesting platform as nonlinear optical materials 1 due to their favourable photophysical properties, such as strong absorption above bandgap, 2 high dielectric constant 3 and the presence of strong excitonic resonances. In particular, high bandgap perovskites 4,5 and systems confined with a high binding energy 6 and large oscillator strength, 7 should give rise to an excellent nonlinear performance. The centrosymmetric crystal structure of halide perovskites allows for third-order nonlinear effects, such as third harmonic generation (THG), light induced modulation and saturable absorption in single crystals of bulk material, 8 polycrystalline thin films 9 and 2D layered perovskites.…”