Open AccessExcitons in PL spectra of Cu(In, Ga)Se-=SUB=-2-=/SUB=- single crystal -=SUP=-*-=/SUP=-
Author(s) -
Ekaterina Skidchenko,
М. V. Yakushev,
Lucia Spasevski,
P. R. Edwards,
М. А. Сулимов,
Robert Martin
Publication year - 2019
Publication title -
fizika tverdogo tela
Language(s) - English
Resource type - Journals
eISSN - 1726-7498
pISSN - 0367-3294
DOI - 10.21883/ftt.2019.05.47609.39f
Subject(s) - exciton , photoluminescence , spectral line , crystal (programming language) , single crystal , spectroscopy , materials science , analytical chemistry (journal) , excitation , crystallography , molecular physics , chemistry , condensed matter physics , physics , optoelectronics , chromatography , quantum mechanics , astronomy , computer science , programming language
A photoluminescence (PL) study of Cu(In,Ga)Se_2 (CIGSe) single crystals, (grown by the vertical Bridgman technique) with the [Ga]/[Ga + In] ratio of 7 and 12% and the [Cu]/[In + Ga] ratio greater than unity, as measured by energy dispersive spectroscopy, is presented. Analysis of the excitation intensity and temperature dependence of the PL spectra suggested the excitonic nature of the observed near-band-edge emissions peaks. Free and bound excitons in CIGSe single crystals with both 7 and 12% Ga content are clearly observed, analyzed and identified. An activation energy of 19 meV is determined for the free exciton in the PL spectra of the sample with 12% Ga. The presence of the excitons demonstrated a high structural quality of the material.