摘要
MgO薄膜被认为是等离子体显示器件中介质保护膜的最理想材料。本文基于第一性原理的密度泛函理论,结合格林函数G和动力学屏蔽库仑相互作用W纠正和Bethe-Salpeter方程的求解,研究了MgO不同晶面取向表面结构的电子特性和光谱特性。在分析不同晶面取向表面能带结构、态密度分布的基础上,估算了相应的二次电子发射系数。结果表明:(100)、(110)和(111)三种晶面取向,(100)禁带宽度最小,二次电子发射系数最大。而(111)晶面吸附氢原子后,禁带宽度显著减小,二次电子发射系数优于(100)晶面,是高Xe、高气压工作气体下等离子体显示器介质保护层材料MgO的优选取向。激子光谱计算结果表明,MgO表面有强激子效应,有利于外电子发射。合理选择MgO晶面取向,可有效提高等离子体显示器放电效率、降低其着火电压,减小Jitter时间。
Motivated for quality improvement of plasma display panel（ PDP）,the electronic structure,absorption spectrum,secondary electron emission coefficient γ and exciton spectrum of various Mg O surfaces were mathematically modeled and theoretically analyzed in first principle calculation,based on the density functional theorycombined with Green＇s function G and the screened Coulomb interaction W-correction and Bethe-Salpeterequation.The calculated results show that Mg O（ 100） has the narrowest gap and largest γ among Mg O（ 100）,Mg O（ 110） and Mg O（ 111）. The Mg O（ 111） with adsorbed H-atom was found to have a much reduced gap-width and a γ larger than that of Mg O（ 100）,suggesting that it is a good orientation in high Xe-content PDP. In addition,as shown in the calculated exciton spectrum,strong exciton effect of Mg O surfaces is more favorable to external electron emission.Reasonable selection of Mg O surface orientation can be useful for increasing discharging efficiency of PDP,reducing firing voltage and Jitter time.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2016年第8期849-855,共7页
Chinese Journal of Vacuum Science and Technology
基金
国家自然科学基金(61271053)
江苏省自然科学基金(BK2012737)
关键词
第一性原理
表面结构
二次电子发射
激子光谱
First-principle theory
Surface structure
The secondary electron emission
Exciton spectrum
