Mechanisms for the creation of intrinsic electron-hole trapping centers in a CaSO4 crystall

T.N Nurakhmetov,A.M Zhunusbekov,B.N Yussupbekova,K.B Zhangylyssov,D.H Daurenbekov,T.T Alibay,D.A Tolekov,B.M Sadykova

doi:10.32523/ejpfm.2021050308

T.N Nurakhmetov, A.M Zhunusbekov + Show 6 more

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https://doi.org/10.32523/ejpfm.2021050308

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Abstract

The mechanism of creation of electron-hole trapping centers in CaSO4 at 15-300 K was investigated by the methods of vacuum-ultraviolet and thermoactivation spectroscopy. It is shown that electron-hole trapping centers are formed upon trap of electrons in the anionic complexes SO4− and localization of holes in the form of SO4− radical. Based on the measurement of the spectrum of excitation of long-wavelength recombination emission at 3.0-3.1 eV and 2.7 eV, the energy distance of the formed electron-hole trapping centers was estimated (4.43 eV and 3.87 eV).

Highlights

Eurasian Journal of Physics and Functional MaterialsMechanisms for the creation of intrinsic electron-hole trapping centers in a CaSO4 crystall
In irradiated CaSO4 crystals with UV photons and X-rays, two types of intrinsic emission arise: a group of short-wavelength emission at 3.7-3.8 eV, 4.1-4.3 eV, 4.5 eV and about 5 eV formed upon excitation by UV photons 6.2-12.3 eV.The second group of long-wavelength emission occurs together with short-wavelength emission at 3.0-3.1 eV, 2.6-2.7 eV, and 2.32.4 eV in almost all irradiated sulfates of alkali and alkaline earth metals
K2SO4, it was assumed that these bands arise when electrons from three subbands of the valence band of the SO24− complex formed from the 2p state of oxygen into the conduction band

Summary

Eurasian Journal of Physics and Functional Materials

Mechanisms for the creation of intrinsic electron-hole trapping centers in a CaSO4 crystall. The mechanism of creation of electron-hole trapping centers in CaSO4 at 15-300 K was investigated by the methods of vacuum-ultraviolet and thermoactivation spectroscopy. It is shown that electron-hole trapping centers are formed upon trap of electrons in the anionic complexes SO24− and localization of holes in the form of SO4− radical. Based on the measurement of the spectrum of excitation of long-wavelength recombination emission at 3.0-3.1 eV and 2.7 eV, the energy distance of the formed electron-hole trapping centers was estimated (4.43 eV and 3.87 eV).

Introduction

Objects and methods of research

The results of the experiment and their discussion

Conclusion