Anisotropic dielectric behavior of layered perovskite-like Cs3Bi2I9 crystals in the terahertz region

Sun, Qihao; Yang, Wenhui; Cheng, Yuanbo; Dong, Jiangpeng; Zhu, Mengqin; Zhang, Binbin; Dubois, Alain; Zhu, Menghua; Wang, Jie; Ye, Xu

doi:10.1039/d0cp04485g

Cited by 7 publications

(6 citation statements)

References 32 publications

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“…In this work, we use COMSOL Multiphysics [46,47] to simulate two rectangular Cs 3 Bi 2 I 9 and p-Si devices, where the optical parameters of the perovskite Cs 3 Bi 2 I 9 nanocrystals are referenced from literature. [48][49][50] In the model for Cs 3 Bi 2 I 9 , we first performed a scan at wavelengths from 200 to 500 nm via keeping the incident light power constant. In Figure 5a, the response of the device tends to rise and then fall with wavelength and the best response is at around 400 nm, which is in perfect agreement with the experimental results of the flexible device (Figure 3b).…”

Section: Resultsmentioning

confidence: 99%

Air‐Stabilized Lead‐Free Hexagonal Cs₃Bi₂I₉ Nanocrystals for Ultrahigh‐Performance Optical Detection

Wang

Liu

et al. 2022

Adv Funct Materials

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Broadband photodetectors possess enormous potentials for diverse applications while it is generally subjected to a lack of active materials with high performances under user-friendly conditions. Bismuth-based perovskites are promising and demonstrate better air stability than lead halide perovskites against moisture, heat, and light. In the present work, lead-free all-inorganic hexagonal Cs 3 Bi 2 I 9 perovskite nanocrystals are successfully fabricated via a modulated colloidal synthetic route. The Cs 3 Bi 2 I 9 nanocrystals are monodispersed with a size of ≈28 nm, which are applied for the construction of flexible Cs 3 Bi 2 I 9 detector and vertical heterogeneous structured photo detector of p-Si/Cs 3 Bi 2 I 9 /graphene. The flexible detector not only demonstrates excellent detective performance, but also yields high-resolution photographs as an imaging sensor. The p-Si/Cs 3 Bi 2 I 9 /graphene photodetector exhibits broad spectral response from ultraviolet to infrared light (254−1064 nm) with microsecond response time (31/34 µs). In particular, it performs with a high responsivity of 23.6 A W −1 and a high specific detectivity of 1.75 × 10 13 Jones under 650 nm illumination even in weak light intensity as low as 1 µW cm −2 , and exhibits excellent stability in ambient air, which is obviously ahead of the previously reported work. In addition, finite element analysis further demonstrates the excellent optoelectronic properties of Cs 3 Bi 2 I 9 materials and the broad spectral response of vertical heterojunctions.

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Section: Resultsmentioning

confidence: 99%

Air‐Stabilized Lead‐Free Hexagonal Cs₃Bi₂I₉ Nanocrystals for Ultrahigh‐Performance Optical Detection

Wang

Liu

et al. 2022

Adv Funct Materials

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“…The higher dielectric constant materials increase charge storage capacity, and the lower dielectric materials could be useful in electronic circuits. The complex dielectric constants measured for MAPbBr 3 (0.6 mm) and MAPbI 3 (0.8 mm) lie between 1.02–7.72 and 1.10–4.57, respectively, which are even higher than that of their inorganic counterpart CsPbBr 3 [ 29 ] and conventional perovskite materials such as SrTiO 3 and Cs 3 Bi 2 I 9 [ 15 , 30 ]. This indicates that MAPbBr 3 and MAPbI 3 are promising materials for charge storage applications and can modulate the performance by simply varying the sample thickness.…”

Section: Resultsmentioning

confidence: 99%

“…Determining the nonlinear optical constants such as the refractive index, absorption coefficients, and dielectric constants at the THz domain is highly important for the design and development of perovskite-based THz devices. Recently, several research groups studied the optical properties of organic–inorganic halide perovskites in the THz range [ 14 , 15 , 16 ]. For example, Nayak et al studied the elemental, optical, and THz-TDS studies on methyl p-hydroxybenzoate SC for THz applications [ 17 ].…”

Section: Introductionmentioning

confidence: 99%

Measurement of Optical Properties of CH3NH3PbX3 (X = Br, I) Single Crystals Using Terahertz Time-Domain Spectroscopy

et al. 2023

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Organometallic lead bromide and iodide perovskite single crystals (PSCs) are potential candidates for terahertz applications. Herein, we performed terahertz time-domain spectroscopy (THz-TDS) in the frequency range of 0.1–3.0 THz on different thicknesses of MAPbBr3 (0.3, 0.6, and 0.8 mm) and MAPbI3 (0.6, 0.8, 0.9, 1.3, and 2.3 mm). The measurements were carried out with respect to the position (along the focal area), azimuthal rotation of the PSCs, and incidence angles of the reference THz pulse on the PSCs’ surface. Based on the transmitted THz pulses from PSCs from the above measurements, we calculated the real and imaginary parts of the refractive index, dielectric constants, absorption coefficients, and dark conductivity. These optical parameters tend to increase with decreases in the PSCs’ thicknesses. The transmission spectra of the terahertz electric field indicate that the measured optical properties do not vary significantly with the position and orientation of PSCs. The real parts of the refractive index and dielectric constants are higher than the imaginary values for both PSCs. On the other hand, a slight blueshift in the optical phonon vibrations corresponding to Pb-Br/I-Pb and Pb-Br/I bonds is observed with an increase in thickness. Interestingly, the phonon vibrations do not vary with the incidence angle of the THz pulses on the same crystal’s surface. The optical parameters based on THz-TDS reveal that the PSCs satisfy the requirement for tunable THz devices which need suitable, sensitive, and stable absorption properties between 0.1 and 3 THz.

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“…For ILs sharing the same anions ( Table 1 and Table S6 ), n D decreases as the length of the alkyl chain in the cations increases. Refractive index correlates with dipole moment [ 39 , 40 ], which increases with higher molecular packing density [ 41 ]. Thus, a larger dipole moment results in a higher refractive index.…”

Section: Resultsmentioning

confidence: 99%

A New Compartmentalized Scale (PN) for Measuring Polarity Applied to Novel Ether-Functionalized Amino Acid Ionic Liquids

Guo

et al. 2022

Molecules

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Functionalized and environmentally friendly ionic liquids are required in many fields, but convenient methods for measuring their polarity are lacking. Two novel ether-functionalized amino acid ionic liquids, 1-(2-methoxyethyl)-3-methylimidazolium alanine ([C1OC2mim][Ala]) and 1-(2-ethoxyethyl)-3-methylimidazolium alanine ([C2OC2mim][Ala]), were synthesized by a neutralization method and their structures confirmed by NMR spectroscopy. Density, surface tension, and refractive index were determined using the standard addition method. The strength of intermolecular interactions within these ionic liquids was examined in terms of standard entropy, lattice energy, and association enthalpy. A new polarity scale, PN, is now proposed, which divides polarity into two compartments: the surface and the body of the liquid. Surface tension is predicted via an improved Lorentz-Lorenz equation, and molar surface entropy is used to determine the polarity of the surface. This new PN scale is based on easily measured physicochemical parameters, is validated against alternative polarity scales, and is applicable to both ionic and molecular liquids.

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Anisotropic dielectric behavior of layered perovskite-like Cs₃Bi₂I₉ crystals in the terahertz region

Abstract: The ternary metal halide perovskites have gradually attracted attentions in the applications of optoelectronic field, due to the tunable crystal structure and appropriate bandgap. Lead free Cs3Bi2I9 perovskite, with the...

Cited by 7 publications

References 32 publications

Air‐Stabilized Lead‐Free Hexagonal Cs₃Bi₂I₉ Nanocrystals for Ultrahigh‐Performance Optical Detection

Air‐Stabilized Lead‐Free Hexagonal Cs₃Bi₂I₉ Nanocrystals for Ultrahigh‐Performance Optical Detection

Measurement of Optical Properties of CH3NH3PbX3 (X = Br, I) Single Crystals Using Terahertz Time-Domain Spectroscopy

A New Compartmentalized Scale (PN) for Measuring Polarity Applied to Novel Ether-Functionalized Amino Acid Ionic Liquids

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Anisotropic dielectric behavior of layered perovskite-like Cs3Bi2I9 crystals in the terahertz region

Abstract: The ternary metal halide perovskites have gradually attracted attentions in the applications of optoelectronic field, due to the tunable crystal structure and appropriate bandgap. Lead free Cs3Bi2I9 perovskite, with the...

Cited by 7 publications

References 32 publications

Air‐Stabilized Lead‐Free Hexagonal Cs3Bi2I9 Nanocrystals for Ultrahigh‐Performance Optical Detection

Air‐Stabilized Lead‐Free Hexagonal Cs3Bi2I9 Nanocrystals for Ultrahigh‐Performance Optical Detection

Measurement of Optical Properties of CH3NH3PbX3 (X = Br, I) Single Crystals Using Terahertz Time-Domain Spectroscopy

A New Compartmentalized Scale (PN) for Measuring Polarity Applied to Novel Ether-Functionalized Amino Acid Ionic Liquids

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Anisotropic dielectric behavior of layered perovskite-like Cs₃Bi₂I₉ crystals in the terahertz region

Air‐Stabilized Lead‐Free Hexagonal Cs₃Bi₂I₉ Nanocrystals for Ultrahigh‐Performance Optical Detection

Air‐Stabilized Lead‐Free Hexagonal Cs₃Bi₂I₉ Nanocrystals for Ultrahigh‐Performance Optical Detection