Exciton lines in luminescence spectra of Ni x Zn 1-x O under inner shell excitation

Abstract

The paper presents the results of the study of two narrow luminescence lines I 1 and I 2 at the energies of 3.339 and 3.393 eV respectively in NiO and solid state solution Ni 0.6 Zn 0.4 O. The luminescence spectroscopy with a sub-nanosecond time resolution upon selective photoexcitation in the energy range of absorption of the inner shells Zn M- and Ni L 2,3 - edges of Zn- and Ni- ions was used to promote proposed earlier mechanism of origin of luminescence lines I 1 and I 2 . Photoluminescence decay kinetics of NiO and solid state solution Ni 0.6 Zn 0.4 O under soft x-ray excitation are discussed. The doublet of I 1 and I 2 lines is believed to arise due to the radiative annihilation of p-d excitons. © 2015 The Authors. Published by Elsevier B.V.