Some peculiarities of the near-band-edge emission from ZnO crystals grown on Si whiskers

Ch. M. Briskina, V. M. Markushev, L. A. Zadorozhnaya, M. E. Givargizov, V. N. Yashkov, I. S. Volchkov, V. M. Kanevsky

Kotel’nikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, Moscow
Shubnikov Institute of Crystallography, Federal Scientific Research Centre ‘Crystallography and Photonics’, Russian Academy of Sciences, Moscow

Abstract: The nature of the room-temperature near-band-edge emission from ZnO nanocrystals formed on Si substrates with whiskers is analysed. The peculiarities of the emission spectra of ZnO grown either directly on whiskers or on a substrate free of whiskers, as well as of ZnO grown on Si whiskers with Au globules on their tips, are studied and compared. Analysis shows that the phonon replica of free exciton emission makes a significant contribution to the luminescence spectrum of ZnO nanocrystals grown on whiskers, with homogeneous broadening dominating in this case. A comparison of the intensities of near-band-edge emission in the samples with and without gold showed that the presence of the latter enhances the emission by a factor of about 3.

Keywords: ZnO, nanocrystals, silicon whiskers, gold, photoluminescence, near-band-edge emission, excitons

This work was performed using equipment of the Shared Research Centre of the FSRC ‘Crystallography and Photonics’ of RAS and supported by the Ministry of Science and Higher Education of the Russian Federation (Project RFMEFI62119X0035) within the state assignments of the FSRC ‘Crystallography and Photonics’ of RAS (in the part concerning the growth of nanostructures) and the Kotelnikov Institute of Radioengineering and Electronics of RAS (in the part concerning the photoluminescence studies).

Received: 15.04.2022