Journal of Luminescence 117 (2006) 90–94 Estimation of the acceleration ability for electrons in SiO 2 and the tunneling effect Fujun Zhang a , Zheng Xu a,b,Ã , Feng Teng a , Shengyi Yang a , Zhidong Lou a , Ling Liu a , Lijian Meng b , Yanbing Hou a , Yongsheng Wang a , Xurong Xu a a Key Laboratory for Information Storage, Display and Materials, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044, PR China b Departamento de Fisica, Instituto Superior de Engenharia do Porto, 4200-072 Porto, Portugal Received 20 January 2005 Available online 31 August 2005 Abstract Silicon dioxide (SiO 2 ) plays an important role in layered optimization scheme and solid-state cathodoluminescence (SSCL). Initially, it was believed that the SiO 2 layer would (i) generate extra interface states contributing to a number of primary electrons available for exciting the luminescent centers, and/or (ii) act as acceleration layer resulted in gaining high energy for those electrons that would tunnel into the luminescent layer to excite luminescent centers. Based on the brightness vs. voltage (B–V) measurements, we deem that the latter case, i.e. acceleration and tunneling, is the dominant mechanism. A detailed discussion in terms of electrons acceleration and tunneling as the main contributions to the enhancement of brightness is presented. r 2005 Elsevier B.V. All rights reserved. PACS: 73.61.Jc; 77.55.+f; 78.60.Fi Keywords: Electron acceleration; Tunneling effect; Inorganic electroluminescence (IEL) 1. Introduction Silicon and silicon oxide were widely studied and used as an alternative dielectric layer and semiconductor material in ultra-large scale inte- grated circuits (ULSI), complementary metal–ox- ide–semiconductor transistor (CMOS) and so on. Silica exists in many forms such as cristobalite, tridymite, quartz and vitreous silica [1,2]. The strong ability of electron heating in SiO 2 was explored by Theis [3]. Silicon oxide is a polar material. It is well known that longitudinal optical (LO) phonons scattering is not sufficient to ARTICLE IN PRESS www.elsevier.com/locate/jlumin 0022-2313/$ - see front matter r 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.jlumin.2005.07.002 Ã Corresponding author. Institute of Optoelectronic Technol- ogy, Beijing, Jiaotong University, Beijing 100044, PR China. Tel.: +86 10 51685072. E-mail addresses: zhang_fj@tom.com (F. Zhang), zhengxu@center.njtu.edu.cn (Z. Xu).