Electron emission during collisions of low-energy ions with MgO(110) Y.T. Matulevich a , T.J. Vink b , L.F. Feiner b , P.A. Zeijlmans van Emmichoven a, * a Debye Institute, Utrecht University, P.O. Box 80000, 3508 TA Utrecht, The Netherlands b Philips Research Laboratories, Prof. Holstlaan 4, 5656 AA Eindhoven, The Netherlands Abstract Electron spectra arising in collisions between low-energy He þ and Ne þ ions and bulk MgO(1 1 0) are reported. For both ions the measured spectra are virtually the same and consist of very-low-energy electrons with energies of up to only about 6 eV. Electron emission originating in Auger neutralization of the primary ions close to the MgO surface is considered. The strong Coulomb interaction between primary ions and O 2 cores may significantly reduce the ion- ization potentials and thereby the final electron energies. Contributions from other neutralization channels can pres- ently not be excluded. Ó 2002 Elsevier Science B.V. All rights reserved. PACS: 79.20.Rf; 79.20.m; 34.70.þe Keywords: Ion–surface interactions; Insulators; Neutralization; Electron emission; Charge exchange 1. Introduction Plasma display panels (PDPs) receive much at- tention in research and development as a key technology to achieve large, flat and light-weight displays [1]. The working principle of nowadays PDPs is based on an AC-driven dielectric barrier discharge of a noble gas mixture (Ne–Xe), which is sustained between a pair of coplanar electrodes. The vacuum ultraviolet light emitted by the gas discharge is used for the excitation of phosphors, which subsequently fluoresce in the visible region. In a PDP cell the electrodes are covered with a glass-like dielectric layer on top of which a thin protective layer is deposited. The protective layer is very important in determining the driving volt- age of the panel and the power consumption. It is well known that a larger secondary electron emission coefficient lowers the driving voltage of a panel [2]. Because of its high secondary electron emission yield and its high stability under ion bombardment, MgO is used as a protective layer in PDPs. Ion induced electron emission from metal sur- faces has been studied extensively in the past [3–7]. For slow ions, with kinetic energies typically below 100 eV, electron emission is mainly induced by neutralization of the ions. It is well established that singly charged noble gas ions interacting with metal surfaces with large work functions (Cu, Ni, W, etc.) are predominantly neutralized by Auger neutralization [3–6]. For metal surfaces with Nuclear Instruments and Methods in Physics Research B 193 (2002) 632–637 www.elsevier.com/locate/nimb * Corresponding author. Tel.: +31-30-2532845; fax: +31-30- 2543165. E-mail address: p.a.zeijlmans@phys.uu.nl (P.A. Zeijlmans van Emmichoven). 0168-583X/02/$ - see front matter Ó 2002 Elsevier Science B.V. All rights reserved. PII:S0168-583X(02)00878-9