Refractive Index Dispersion of Organic–Inorganic Hybrid Halide Perovskite CH₃NH₃PbX₃ (X═Cl, Br, I) Single Crystals

Abstract

Optical dispersion properties are indispensable in the thorough design of modern perovskite‐based photonics devices. Based on inverse temperature crystallization (ITC) method, here, CH3NH3PbX3 (CH3NH3═MA, X═Cl, Br, I) bulk single crystals are grown from precursor solution. X‐ray patterns indicate that the perovskite crystals have good crystallinity. MAPbCl3, MAPbBr3, and MAPbI3 crystals are transparent above 427, 574, and 823 nm, respectively. Refractive indices of MAPbX3 crystals are measured with different wavelength at 24 °C and reduced dramatically with the wavelength increase. Sellmeier dispersion equation fitted by least squares can be used to calculate the refractive index above the absorption edges. Refractive indices rank in the order of MAPbI3 > MAPbBr3 > MAPbCl3 at the same wavelength. The halogen elements have great influence on refractive indices. These results play a vital role in studying MAPbX3 nonlinear optical properties as well as in further designing photoelectric devices.

Optimization of the Growth Conditions for High Quality CH3NH3PbBr3 Hybrid Perovskite Single Crystals

“…To better evidence the impact of the bulk of the samples, Fresnel losses and sample thickness were taken into consideration using the optical index n of the material from ref. 17 leading to the linear attenuation coefficients calculated from the following equation: 18…”

Optical dispersion and bandgap of pure and Mn‐doped 0.92Na0.5Bi0.5TiO3‐0.08K0.5Bi0.5TiO3 lead‐free single crystals

“…In transparent region, refractive index can be accurately calculated by the modified Sellmeier equation: where λ is wavelength in micrometer and A , B , C , and D are constants. The constants can be obtained by the least square fitting with Equation ().…”

“…Despite Equation () can precisely calculate the refractive index n over a long range of wavelength, the constants in the equation do not possess definite physical meanings. Wemple and DiDomenico proposed the single‐oscillator dispersion relation based on the single‐oscillator approximation:where n is refractive index, E is the energy of incident light, λ is the incident wavelength, S 0 is the average oscillator strength, λ 0 is the average oscillator position, E d is the dispersion energy, and E 0 is the single‐oscillator energy. The linear fitting curves of ( n 2 −1) −1 versus λ −2 and E 2 are shown in Figure and the related coefficients above are summarized in Table .…”

Asymptotic analysis of subwavelength halide perovskite resonators

“…We refer to [14] for the values of these constants for different halide perovskites at room temperature. Meanwhile, the dispersion relation for the halide perovskites is observed [10] to take the simplified form…”

“…where n is the refractive index, k is the wavenumber and S 0 and λ 0 are positive constants that describe the average oscillator strength, see [10] for the values for some different halide perovsksites.…”