Diffuse Reflectance Spectroscopy with Dilution: A Powerful Method for Halide Perovskites Study

Abstract

Halide perovskites and their low-dimensional analogs are promising semiconductor materials for solar cells, LEDs, lasers, detectors and other applications in the area of photonics. The most informative optical property of semiconductor photonics materials is the absorption spectrum enabling observation of the fundamental absorption edge, exciton structure, defect-related bands, etc. Traditionally, in the study of halide perovskites, this spectrum is obtained by absorption spectroscopy of thin films or diffuse reflectance spectroscopy of powders. The first method is applicable only to compounds with the developed thin film deposition technology, and in the second case, a large absorption coefficient narrows the observations down to the sample transparency region. In this paper, we suggest the diffuse reflectance spectroscopy with dilution as a method for obtaining the full-range absorption spectrum from halide perovskite powders, and demonstrate its application to practically important cases.

Low-Temperature Refractive Index Dispersion in MAPbI3 Halide Perovskite Single Crystal

“…35 The transition at E 1 coincides with the excitonic transition at the direct interband transition between the maximum of the valence band and the minimum of the conduction band at Rpoint. 23,26 Attribution of the higher-lying transition at E 2 is more doubtful. One possible explanation is a transition at the M-point.…”

Direction Switching and Self‐Recovering Mechanochromic Luminescence of Anthracene‐Modified o‐Carboranes

“…Furthermore, the additional measurement was performed to obtain the detail information about the difference in molecular arrangements between crystal and amorphous. We focused on the fact that the molecular structures and arrangements in the solid samples can be evaluated from the diffuse reflectance spectra [35,36] . In general, from solid samples with π‐stacked structures, red‐shifted spectra can be obtained compared to the corresponding non‐π‐stacked sample [37] .…”

“…We focused on the fact that the molecular structures and arrangements in the solid samples can be evaluated from the diffuse reflectance spectra. [35,36] In general, from solid samples with π-stacked structures, red-shifted spectra can be obtained compared to the corresponding non-π-stacked sample. [37] Taking this issue into consideration, we evaluated our molecules.…”

Absorption Edge Fine Structure in the PyPbI3 Perovskite Revealed by Variable-Temperature UV–Vis Diffuse Reflectance Spectroscopy

“…However, improving the resolution of the absorption bands in DR spectra of colored materials can be achieved by dilution of a powder sample in a nonabsorbing matrix. In this regard, several examples have already appeared that applied this dilution method to examine the absorption spectra of conventional semiconductors such as, for instance, V 2 O 5 , carbon and ZnO, and most recently for several perovskites . Yet no studies have been forthcoming in the application of this dilution to study a semiconductor that might demonstrate a complex absorption edge.…”

“…In this regard, several examples have already appeared that applied this dilution method to examine the absorption spectra of conventional semiconductors such as, for instance, V 2 O 5 , 21 carbon and ZnO, 22 and most recently for several perovskites. 23 Yet no studies have been forthcoming in the application of this dilution to study a semiconductor that might demonstrate a complex absorption edge. Accordingly, this motivated us to examine the temperature dependences of the DR spectra of PyPbI 3 diluted in a BaSO 4 powder matrix.…”