分子束外延生长的n型Al掺杂ZnS_(1-x)Te_x深中心研究  

DEEP ELECTRON STATES IN n TYPE Al DOPED ZnS1-xTex GROWN BY MOLECULAR BEAM EPITAXY

作　　者：卢励吾[1] 张砚华[1] 

机构地区：[1]中国科学院半导体研究所半导体材料科学开放研究实验室

出　　处：《物理学报》1998年第2期286-293,共8页Acta Physica Sinica

基　　金：国家自然科学基金;中国科学院半导体材料科学开放研究实验室和香港科技大学资助的课题

摘　　要：应用电容电压、光致荧光和深能级瞬态谱技术研究了分子束外延生长的ｎ型Ａｌ掺杂ＺｎＳ１－ｘＴｅｘ外延层深中心．Ａｌ掺杂ＺｎＳ０９７７Ｔｅ００２３的光致荧光强度明显低于不掺杂的ＺｎＳ０９７７Ｔｅ００２３，这表明一部分Ａｌ原子形成非辐射深中心．Ａｌ掺杂ＺｎＳ１－ｘＴｅｘ（ｘ＝０，００１７，００４和００４６）的深能级瞬态傅里叶谱表明，Ａｌ引进导带下的０２１和０３９ｅＶ电子陷阱，Ｔｅ除了作为材料合金的成分和等电子中心外，还涉及到一个电子陷阱的形成，其相对于导带的能级位置随Ｔｅ组分增加而减小．实验结果还表明仅有少量掺杂的Ａｌ原子形成非辐射中心。Abstract Capacitance voltage (C V), photoluminescence (PL) and deep level transient spectroscopy (DLTS) techniques were used to investigate deep electron states in n type Al doped ZnS1-xTex epilayers grown by molecular beam epitaxy (MBE). The integrated intensity of the PL spectra obtained from Al doped ZnS0977Te0023 is lower than that of undoped ZnS0977Te0023,indicating that some of Al atoms form nonradiative deep traps. Deep level transient Fourier spectroscopy (DLTFS) spectra of the Al doped ZnS1-xTex(x=0,0.017,0.04 and 0.046,respectively) epilayers reveal that Al doping leads to the formation of two electron traps at 0.21 and 0.39eV below the conduction band. DLTFS results suggest that in addition to the roles of Te as a component of the alloy as well as isoelectronic centers, Te is also involved in the formation of an electron trap, whose energy level relative to the conduction band decreases as Te concentration increases. Our results show that only a small fraction of Al atoms form nonradiative deep defects, indicating clearly that Al is indeed a very good donor impurity for ZnS1-xTexepilayers in the range of Te concentration studied in this work.

关 键 词：硫化锌 深中心 分子束外延生长 N型 铝掺杂 

分 类 号：TN304.22[电子电信—物理电子学] TN304.054