scholarly journals Urbach’s tail in the absorption spectra of Cu2GeSe3 semiconducting compound

2018 ◽  
Vol 65 (1) ◽  
pp. 5 ◽  
Author(s):  
Carlos Gustavo Rincón
Keyword(s):  
Absorption Spectra ◽  
Small Deviation ◽  
Structural Disorder ◽  
Phonon Energy ◽  
Phonon Interaction ◽  
Ideal Stoichiometry ◽  
Mn Doped

In the present work we report on the analysis of the Urbach’s tail in pure and Mn-doped Cu2GeSe3 samples having small deviation from its ideal stoichiometry. It is found that the high values of the phonon energy hnp involved in the electrons/excitons-phonon interaction in the formation of this tail are due to structural disorder caused by deviation from ideal stoichiometry. Values of hnp for pure and doped samples were found to be 48, 60 and 81 meV, respectively, whereas the phonon energy for an entirely ordered Cu2GeSe3 sample was estimated to be about 25 meV.

The influence of polaron–phonon interaction on absorption spectra in molecular crystals

2009 ◽  
Vol 480 (1-3) ◽  
pp. 75-81 ◽  
Author(s):  
Dalibor Čevizović ◽  
Slobodan Zeković ◽  
Zoran Ivić
Keyword(s):  
Absorption Spectra ◽  
Molecular Crystals ◽  
Phonon Interaction

scholarly journals Анализ температурной зависимости спектров экситонной люминесценции квантовых точек селенида кадмия, выращенных в жидкокристаллической матрице-=SUP=-*-=/SUP=-

2019 ◽  
Vol 126 (1) ◽  
pp. 50
Author(s):  
К.А. Магарян ◽  
К.Р. Каримуллин ◽  
И.А. Васильева ◽  
А.В. Наумов
Keyword(s):  
Quantum Dots ◽  
Liquid Crystal ◽  
Theoretical Model ◽  
Phonon Energy ◽  
Luminescence Spectra ◽  
Cdse Quantum Dots ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Temperature Dependences ◽  
Rhys Factor

AbstractThe temperature dependences of the positions of maxima of exciton bands in the luminescence spectra of liquid crystal nanocomposites with CdSe quantum dots with sizes of 1.8 and 2.3 nm at T = 77–300 K have been analyzed. The analysis under the theoretical model taking into account the electron–phonon interaction inside quantum dots has made it possible to calculate the values of the Huang–Rhys factor and average phonon energy in nanocrystals under study.

First Observation of the Urbach Tail in a Multicomponent Organic System

1992 ◽  
Vol 46 (2) ◽  
pp. 354-356 ◽  
Author(s):  
Oliver C. Mullins ◽  
Yifu Zhu
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Spectral Region ◽  
Structural Disorder ◽  
Organic System ◽  
Urbach Tail

The exponential attenuation of electronic absorption in spectral regions removed from the absorption maxima, the “Urbach tail,” has been observed in a variety of materials and has been ascribed to thermal and structural disorder. Here, we report, to our knowledge, the first observation of the Urbach tail in a multicomponent organic system (the asphaltenes) which is due, in part, to the overlapping absorption spectra of the diverse component chromophores within the tail spectral region. The distribution of chromophores produces an unusually large, nonthermal width in the Urbach tail.

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