Fizika Nizkikh Temperatur: Volume 45, Number 2 (February 2019), p. 258-262 ( to contents , go back )
The manifestation of excitons in low-temperature luminescence spectra of solid solutions of zinc and nickel oxides
V.N. Churmanov2, V.I. Sokolov1, V.A. Pustovarov2, N.B. Gruzdev1, and V.Yu. Ivanov2
1M.N. Mikheev Institute of Metal Physics, Ural Branch of the Russian Academy of Sciences Yekaterinburg 620108, Russia
2Ural Federal University, Yekaterinburg 620002, Russia
Received October 9, 2018, published online December 20, 2018
The given paper is devoted to investigation of the x-ray lumi-nescence spectra of Zn1–xNix solid solutions of a number of concentrations, including NiO (x = 1) around the lines I1 and I2 with energies of 3,339 and 3,393 eV correspondingly. Earlier a strong temperature dependence on these lines similar to the one manifesting itself during observation of the donor and acceptor excitons of 3d-impurities in II–VI:3d compounds had been discovered, along with the changing of ratio of intensities with the increasing of temperature and different decay kinetics, which allowed us to assume the origin of I1 and I2 lines with radiative annihilation of excitons with the different physical nature. The results achieved in the study allowed the authors to confirm the fact that the width of bandgap in the given compounds does not depend on their composition (i.e., on concentration x) and in NiO near the bottom of the conduction band a number of states of nickel of both d- and s-types exists. Basing on the conducted analysis of electronic energy spectrum, calculated for the investigated solid solutions Zn1–xNixO it was concluded that one of the lines of the x-ray luminescence spectrum is connected with the exciton of the s–p-type, and the other with the exciton of the p–d-type.
Key words: Zn1–xNixO solid solutions, excitons, luminescence, wide gap semiconductors.