Morphology and optical properties of MgO thin films on Mo(001)

Authors :: Stefania Benedetti
Niklas Nilius
Hans-Joachim Freund
Sergio Valeri
Hadj-Mohamed Benia
Source :: Chemical Physics Letters, Chemical physics letters, 430 (2006): 330–335., info:cnr-pdr/source/autori:Benedetti, S; Benia, HM; Nilius, N; Valeri, S; Freund, HJ/titolo:Morphology and optical properties of MgO thin films on Mo(001)/doi:/rivista:Chemical physics letters (Print)/anno:2006/pagina_da:330/pagina_a:335/intervallo_pagine:330–335/volume:430
Publication Year :: 2006
Publisher :: Elsevier BV, 2006.
Abstract: Thin MgO films with a nominal thickness ranging between 1 and 60 ML have been grown on a Mo(001) surface. The film morphology was studied by LEED and STM, revealing the presence of a coincidence pattern with the Mo support in the low coverage regime, a dislocation network at medium thickness and a rather flat and defect-poor MgO surface for thicker layers. The MgO optical properties were investigated as a function of film thickness by analyzing electro-luminescence spectra obtained via electron injection from the STM tip into well-defined surface areas. The spectra are characterized by two distinct emission bands at 3.1 and 4.4 eV. Their origin is discussed in the light of earlier photo-luminescence measurements on MgO nanocubes and smokes. (c) 2006 Elsevier B.V. All rights reserved.