摘要
应变的Ge_xSi_(1-x)层和未应变的硅层间的能带偏移主要是价带偏移。量子阱中载流子的热发射能与界面的能带偏移有着密切的关系。本文用深能级瞬态谱(DLTS)研究分子束外延生长的p型Si/Ge_(0.25)Si_(0.75)/Si单量子阱的价带偏移,阱宽为15nm,考虑到电场的影响和量子阱中第一子能级的位置,对从DLTS得到的热发射能进行适当的修正,可以计算出Si/Ge_(0.25)Si_(0.75)/Si的价带偏移为0.19eV,与理论值符合尚好。本文还讨论了量子阱中载流子的发射、俘获过程与深能级陷阱中载流子的发射、俘获过程之间的异同。
The band offset between strained Ge_xSi(1-x)and unstrained Si is mainly due to the valence band offset ΔE_v. The thermal emission energy from a quantum well is related to the appropriate band offset. The single quantum well (p type Si/Ge(0.25)Si(0.75)/Si) samples were grown by molecular beam epitaxy (MBE), the width of quantum well is 15nm. Deep leve transient spectroscopy (DLTS) measurement have been used to study the valence band offset. After considering the band bending due to the electric field and the first subband energy, the valence band offset ΔEv of the single quantum well was estimated as about 0.19eV, it is in reasonable agreement with theoretical results. The same and difference of emission and capture processess between quantum well and deep level defects were discussed.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1993年第7期1153-1159,共7页
Acta Physica Sinica
基金
国家自然科学基金资助的课题
