Light Absorption Coefficient of CsPbBr₃ Perovskite Nanocrystals

Abstract

Inductively coupled plasma mass spectrometry (ICP-MS) was combined with UV-vis absorption spectroscopy and transmission electron microscopy to determine the size, composition, and intrinsic absorption coefficient μ of 4 to 11 nm sized colloidal CsPbBr nanocrystals (NCs). The ICP-MS measurements demonstrate the nonstoichiometric nature of the NCs, with a systematic excess of lead for all samples studied. Rutherford backscattering measurements indicate that this enrichment in lead concurs with a relative increase in the bromide content. At high photon energies, μ is independent of the nanocrystal size. This allows the nanocrystal concentration in CsPbBr nanocolloids to be readily obtained by a combination of absorption spectroscopy and the CsPbBr sizing curve.

Mechanisms of triplet energy transfer across the inorganic nanocrystal/organic molecule interface

“…In this case, the overall TET yield is determined by the hole transfer yield. Indeed, the triplet formation yield, estimated using the maximum signal amplitudes of 3 TCA* absorption and NC bleach and the extinction coefficients reported for TCA triplets 1 and NCs 49 ( Supplementary Note 3), is~94.8%, similar to the TET yield determined from kinetic parameters. We note that the very weak 3 TCA* signal observed in Fig.…”

4‐5: Quantum Dot Design Criteria for Color Conversion in MicroLED Displays

“…This implies that the extinction coefficient is proportional to the volume of the QD, V QD , or equivalently to d 3 where d is QD diameter. This relationship has been demonstrated experimentally in a number of cases [9][10][11]. The intrinsic absorption coefficient is given as:…”

“…Many articles [4][5][6][7][8][9] have been published on the absorption characteristics of various material systems, but usually without specific consideration to absorption in the range of 450 nm, which is the wavelength range typically used as the blue primary in display applications. Absorption relationships are often presented in these publications at shorter wavelengths, in which cases we scaled the relationship to 450nm by digitizing the shape of the published absorption spectrum in order to obtain the absorption at 450nm.…”

“…Perovskite nanoparticles are unique in that they are cubic in shape, rather than spherical, and are not implemented with a shell, so their composition and absorption properties are uniform throughout each particle. They are also known to exhibit a size-independent intrinsic absorption coefficient [9] making it simple to calculate ensemble absorption properties, as shown in Figure 5 for both OD1 and OD2 cases.…”

2D and Quasi‐2D Halide Perovskites: Applications and Progress

“…Since photovoltaics have been targeted as promising energy sources, the halide perovskites (HPs) have been most intensively studied for the past 5 years due to their excellent optical and electronic properties such as excellent light absorption coefficient, high external quantum efficiency (EQE), and long charge carrier diffusion length, creating a huge impact on the semiconductor research and technology fields . The three‐dimensional (3D) HPs have ABX 3 (A: monovalent cations, B: divalent cations, X: halide anions) frameworks corresponding to corner‐sharing octahedral networks features compositional flexibility, and they can be properly optimized by constituent tuning of A, B, and X components for desired characteristics .…”