论文部分内容阅读
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 the strained Ge_xSi_ (1-x) layer and the unstrained silicon layer is mainly the valence band offset. The thermal emission energy of carriers in the quantum well is closely related to the band offset of the interface. In this paper, we study the valence band shift of a p-type Si / Ge_ (0.25) Si_ (0.75) / Si single quantum well grown by molecular beam epitaxy using deep level transient spectroscopy (DLTS) with well width of 15 nm. Considering the effect of electric field And the position of the first sub-level in the quantum well, the thermal emission energy obtained from the DLTS can be appropriately corrected to calculate the valence band offset of Si / Ge_ (0.25) Si_ (0.75) / Si of 0.19eV and The theoretical value is still good. This paper also discusses the similarities and differences between the carrier emission and capture processes in quantum wells and the carrier emission and capture processes in deep level traps.