Calculation of the Quasiparticle Energies of Electrons and the Exciton Spectrum in the Region of the Fundamental Absorption Edge in a Perovskite Crystal KMgF3

Authors S.V. Syrotyuk , V.M. Shved , Yu.V. Klysko

Lviv Polytechnic National University, 12, S. Bandera Str., 79013 Lviv, Ukraine

Issue Volume 10, Year 2018, Number 3
Dates Received 02 March 2018; published online 25 June 2018
Citation S.V. Syrotyuk , V.M. Shved, Yu.V. Klysko, J. Nano- Electron. Phys. 10 No 3, 03033 (2018)
PACS Number(s) 71.15.Mb, 71.20.Nr, 71.35. ±
Keywords Fluoroperovskite, GGA approach, Quasiparticles, Exciton energy, Absorption spectrum.

In this paper, the electronic and optical properties of the most effective KMgF3 material are studied, thin films of which are used as a solid-state vacuum ultraviolet phosphor. At the first stage, we obtained wave functions in the framework of the electron density functional GGA. In the second stage, we calculated the improved value of the band gap using the Green's function (approximation GW), constructed on the wave functions calculated in the GGA approximation. We found that the band gap evaluated within the GGA method is about 4.73 eV less than the experimental value. At the third stage the absorption spectrum of the material was calculated on the basis of data obtained in the previous steps. For the first time, quasiparticle electron energies and the absorption spectrum on their basis are found.

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