摘要
利用低压MOCVD技术在(0002)蓝宝石上外延获得高质量的ZnO∶Ga单晶薄膜,并研究了Ga的不同掺杂浓度对材料电学和光学特性的影响.当Ga/Zn气相摩尔比为3.2at%时,ZnO(0002)峰半高宽仅为0.26°,载流子浓度高达2.47×1019cm-3,透射率高于90%;当载流子浓度升高时,吸收边出现明显的Burstein-Moss蓝移效应.同时室温光致发光谱显示,紫外峰位随载流子浓度的增加而发生红移,峰形展宽,这和Ga高掺杂所引起的能带重整化效应有关.当Ga/Zn比达到6.3at%时,由于高掺杂浓度下Ga的自补偿效应导致载流子浓度下降.
High-quality single-crystal Ga doped ZnO films successfully deposited on （0002） a sapphire substrate by a low-pressure metal organic chemical vapor deposition technique. As grown at the Ga/Zn gas molar ratio of 3.2 at%, the film shows a narrow full width at a half maximum of 0.26°,a high carrier concentration of 2.47 × 10^19cm^-3 , and high transmittance of over 90%. With the increase in carrier concentration, Burstein-Moss effect is observed with an obvious blue shift of the absorption edge. Meanwhile,room temperature photoluminescence measurements show that the UV band is broadened and shifted to low energy with the increasing of carrier concentration,which is related to the band-gap renormalization effect. As the Ga/Zn gasphase ratio increases up to 6.3 at%, the carrier concentration decreases greatly, which is possibly due to the self-compensation effect in heavily doped semiconductors.
基金
国家重点基础研究发展规划(批准号:G001CB3095)
国家自然科学基金(批准号:60276011
60390073)
国家高技术研究发展计划(批准号:2002AA311060)资助项目~~
作者简介
朱顺明 工程师，主要从事宽带隙半导体材料的生长与物性研究．
顾书林 本文通信作者，教授，目前主要从事宽带隙半导体材料的生长及其半导体器件的研制．Email：hmdl@nju．edu．cn
