%0 Journal Article
%T INVESTIGATION OF FREE EXCITONS IN UNDOPED MOCVD GaAs EPITAXIAL LAYER OF DIFFERENT THICKNESSES BY PHOTOCONDUCTIVITY<br>用光电导研究不同厚度未掺杂MOCVD GaAs外延层自由激子
%A Wu Fengmei
%A Shi Yi
%A <br>吴凤美
%A Paren.
%A M
%J 红外与毫米波学报
%D 1995
%I Science Press
%X he properties of the free-exciton transitions in undoped MOCVD GaAs epitaxial layer of thicknesses varying from 4 to 30 Urn were determined by using the photoconductivity measurements.It was found that as the thickness is increased,the binding energy R.increases,and the free exciton peak for n=1 shifts slightly towards lower energies,but both the intensity of the higher excitonic levels and the lifetime T of the excitons decrease.These effects were attributed mainly to the defects and electrical field near the surface of the epilayer.Finally,the photoluminescence results and the influence of the measurement temperature on them were also discussed.
%K GaAs epitaxial layer
%K free exciton
%K photoconductivity
%K photoluminescence<br>外延层
%K 自由激子
%K 光电导
%K 光致发光
%K 砷化镓
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=5B3AB970F71A803DEACDC0559115BFCF0A068CD97DD29835&cid=1319827C0C74AAE8D654BEA21B7F54D3&jid=D3B4F771D1A06062008B4D0A2EF05996&aid=FD96C4350772FA2A6BA32F8E7A2F9694&yid=BBCD5003575B2B5F&vid=F3583C8E78166B9E&iid=E158A972A605785F&sid=96A53C367B5173D7&eid=B7BFA4B351E4C682&journal_id=1001-9014&journal_name=红外与毫米波学报&referenced_num=0&reference_num=0