Stability enhancement and pronounced three-photon absorption in SrCl₂-doped FAPbBr₃nano crystals

Abstract

Size-dependent perovskite nanocrystals (PNCs) have manifested tremendous improvement in nonlinear optical (NLO) studies owing to their remarkable optical and electrical properties.

Optical Nonlinearity of Semiconducting Cd(II) Metallogel in the Femtosecond Regime with Two-, Three-, and Four-Photon Absorption

“…The 3PA coefficient is γ = (9.79 ± 0.10) × 10 –4 cm 3 /GW 2 at an intensity of 93 GW/cm 2 . The obtained 3PA absorption coefficient is higher than the value of other materials such as SrCl 2 -doped FAPbBr 3 perovskite nanocrystal . The fifth-order nonlinear susceptibility, χ (5) , is attributed to the 3PA process.…”

“…The obtained 3PA absorption coefficient is higher than the value of other materials such as SrCl 2 -doped FAPbBr 3 perovskite nanocrystal. 53 The fifth-order nonlinear susceptibility, χ (5) , is attributed to the 3PA process. (iv) The open-aperture data at 1000 nm (hυ = 1.24 eV, where 4hυ > E g > 3hυ) fit well for n = 4, at high intensities, providing the 4PA coefficients.…”

Tunable near-infrared emission and three-photon absorption in lanthanide-doped double perovskite nanocrystals

“…30 The NLO characteristics of Cs 2 AgBiBr 6 double perovskite NCs were examined with a 2PA cross-section of ∼1906 GM and a 2PA coefficient of ∼10 −11 cm W −1 by Zhang et al 31 Furthermore, they have also determined the nonlinear absorption coefficient of Cs 4 Cu x Ag 2−2 x Sb 2 Cl 12 nanocrystals to be ∼10 −8 cm W −1 using an 800 nm, 500 Hz fs laser. 32 Khanam et al 33 studied the three-photon absorption (3PA) coefficient of SrCl 2 -doped FAPbBr 3 NCs and obtained a 3PA cross-section of ∼10 −77 cm 6 s 2 . Our group has carried out broadband ultrafast nonlinear optical studies of zero-dimensional Cs 4 PbBr 6 perovskite films 34 and CsPbBr 3 NCs, 35 unveiling their photonic responses in the NLO domain.…”

Aromatic Additives Boost the Terahertz Properties of Mixed Halide Perovskite Single Crystals

“…As in MH–PEA, the bandgap evolution inflection point (or the phase boundary between the single-phase double-halide alloy and phase segregation) consistently increased with an increased N content. Panels c and d of Figure indicate a more comprehensive single-phase range full width half maximum (FWHM) and greater tolerance to phase segregation in the perovskite with a higher Br content than that of MH–PXA with a higher Cl content . Subsequently, the microstrain values have been calculated from p-XRD data using Williamson–Hall (W–H) plots, at 8.436 × 10 –4 , 8.140 × 10 –4 , and 0.950 for MH, MH–PEA, and MH–PXA, respectively (panels a–c of Figure S4 of the Supporting Information) .…”

“…Panels c and d of Figure 3 indicate a more comprehensive single-phase range full width half maximum (FWHM) and greater tolerance to phase segregation in the perovskite with a higher Br content than that of MH−PXA with a higher Cl content. 49 Subsequently, the microstrain values have been calculated from p-XRD data using Williamson−Hall (W−H) plots, at 8.436 × 10 −4 , 8.140 × 10 −4 , and 0.950 for MH, MH−PEA, and MH−PXA, respectively (panels a−c of Figure S4 of the Supporting Information). 50 A higher lattice strain is observed in the case of MH−PXA with more FWHM and peak splitting, which might be due to increased intrinsic defects as a result of halide segregation on the surface of PSCs.…”