Wide-Band-Gap Metal-Free Perovskite for Third-Order Nonlinear Optics

Abstract

This paper establishes the potential of the recently introduced ABX3 metal-free perovskite structures for third-order nonlinear optical processes. The base unit in this family of materials is an ammonium halide octahedra, and it incorporates a large aromatic cation spacer forming the classic perovskite structure. This work shows that the choice of cation is key to the resulting third-order nonlinearity, where the incorporation of “MDABCO” into the structure, a very polar cation, results in a third-order nonlinear refractive index on the order of 10–17 m2 W–1 and high laser damage threshold of 0.8 J cm–2. Owing to its very wide band gap of ∼5.12 eV, this material exhibits a high nonlinear figure of merit across the visible and near-infrared transmission windows. These results show that the metal-free family of perovskite materials is an excellent candidate for nonlinear optics in the important visible and near-infrared wavelength regimes.

Metal‐Free Perovskite Piezoelectric Nanogenerators for Human–Machine Interfaces and Self‐Powered Electrical Stimulation Applications

“…The peak intensity of (200) increases with the precursor concentration, which can be attributed to the preferred orientation induced by high precursor concentration during the growth process. [ 33 , 34 ] Figure 1c shows the XRD patterns of the thin film prepared by different preheating temperatures (room temperature, 100, 120, and 140 ℃). [ 31 , 33 ] The full width at half maximum (FWHM) of the peak (200) decreases with increased preheating temperature, indicating the formation of grains with larger grain size (Table S1 , Supporting Information).…”

“…[ 33 , 34 ] Figure 1c shows the XRD patterns of the thin film prepared by different preheating temperatures (room temperature, 100, 120, and 140 ℃). [ 31 , 33 ] The full width at half maximum (FWHM) of the peak (200) decreases with increased preheating temperature, indicating the formation of grains with larger grain size (Table S1 , Supporting Information). [ 35 ] Additionally, differential scanning calorimetry (DSC) measurement is conducted to understand the structural phase transition of MDABCO‐NH 4 I 3 films, as shown in Figure S1 (Supporting Information).…”

Structural and Functional Insights into Metal-Free Perovskites

“…Moreover, organic content softens the compounds, which assists the facile growth of large-area and high-quality thin films 61. We have witnessed the successful deposition of MDABCO-NH 4 I 3 thin films onto silica substrates via simple single-source evaporation, and the films displayed a highly uniform and transparent glasslike appearance without pinholes 62. All these results motivate the integration of MFP materials into flexible electronics.…”

“…61 We have witnessed the successful deposition of MDABCO-NH 4 I 3 thin films onto silica substrates via simple single-source evaporation, and the films displayed a highly uniform and transparent glasslike appearance without pinholes. 62 All these results motivate the integration of MFP materials into flexible electronics. making MFPs suitable for use in wearable devices and bionics.…”

Pyroelectric and Piezoelectric Voltage Coefficients of Blue Luminescent Organic Lead-Free Perovskite MDABCO-NH₄I₃ Electrospun Nanofibers

“…At high wavelengths (low photon energies), both free perovskite and electrospun fibers containing the perovskite are highly transparent, and the absorption becomes stronger at the band-gap energy. High transparency in the visible and near infrared-red regions of the optical spectra is important for linear and nonlinear optical applications [32,33].…”