Real space transfer of electrons in a Si-based quantum structure and its application to infrared generation

带内跃迁在实现发光硅方面有希望，因为它不会受到硅不可避免的间接带隙的影响。在这项研究中，我们探索了伪晶SiGe/Si异质结构中电子的真实空间转移，试图通过子带间跃迁产生红外辐射。级联设计被广泛接受为子带间发光的代表性设计。然而，量子屏障、共振态可调的超态是使其成为最先进技术的一些原因，这些技术非常复杂，因此不容易移植到sige系统中。这里考虑的是一个由量子阱基态及其势垒组成的两能级系统。载流子将被实空间转移到具有低漂移迁移率的势垒，因为它们沿着量子阱加速，具有更高的迁移率，达到多余动能允许松弛的点。本文报道了SiGe/Si异质结构中载流子的实际空间转移特性，以及基于SiGe- oi衬底的光/载流子约束的尝试。载流子的迁移率通过光学手段进行评估，使用掩膜飞行时间技术，测量激子的双极性扩散率。另一个阱的扩散系数为10cm^2/s，随温度升高而增大，但在100K以上，载流子的热逸阻碍了测量。无论构成通道的是SiGe还是Si，迁移率值都没有太大的差异，这表明在相当大的Ge含量下，我们必须选择窄的宽度来满足势垒的能量天花板，因此由于粗糙度散射，迁移率不可避免地减少。结合束缚态能量计算，这表明人们应该瞄准小锗含量和宽阱或单一异质结构而不是量子阱。由于电偏置和声子散射，在i型SiGe/Si量子阱中清楚地观察到电子的真实空间转移，这使我们偶然地开发了由Si制成的颜色可调光发射器。同时指出，电流注入下的红外光谱应避免与样品黑体辐射等背景相混淆。另一方面，为了本研究的目的，高能离子注入被发现对SiGe-OI衬底的产生至关重要。除此之外，通过一系列的发光实验发现，在增加的激发密度下，可能与增益竞争的耗散俄歇复合可以通过实现SiGe/Si异质结构来抑制。少

Intra-band transitions hold promise in realizing light-emitting silicon in that it does not suffer from the otherwise inextricable indirect band-gap of Si. In this study, we explored real space transfer of electrons in pseudomorphic SiGe/Si heterosturctrues in an attempt to generate infrared radiation due to intersubband transitions.A cascade design is widely accepted as being representative in terms of intersubband luminescence. Quantum barriers, superlatices with tuned resonance states, however, are some of what make it arguably the state-of-the-art technology, which is highly complicated and as such not easily transplanted into the SiGe-system. A two level system consisting of the ground state of a quantum well with its potential barrier was considered here instead. Carriers will be real-space-transferred to the barrer with a low drift mobility as they are accelerated along the quantum well having a higher mobility to the point where excess kinetic energy allows relaxation to set in … More via scattering.Here we report the characteristics of real space transfer of carriers in SiGe/Si heterostructures and the attempt of light/carrier confinement based on a SiGe-OI substrate. Carrier mobilities were evaluated by optical means using a masked time-of-flight technique, which measures the ambipolar diffusivity of excitons. The diffusivity of the other of 10cm^2/s was obtained, which increased with increasing temperature while the thermal escape of carriers from the well hampered the measurement above 100K. The mobility values were not much different regardless of what constitutes the channel, SiGe or Si, which indicates that the mobility inevitably dwindled due to the roughness scattering because we had to choose a narrow width to comply with the energy ceiling of the potential barrier at a fairly large Ge content. This along with bound-state energy calculation suggests that one should target a small Ge content and a wide well or a single-heterostructure rather than quantum well. Real space transfer of electrons due to both electric biasing and phonon scattering was clearly observed in type-I SiGe/Si quantum wells, which fortuitously allowed us to develop a color-tunable light-emitter made of Si. It is also pointed out that spectroscopy of infrared generation under current injection should avoid the confusion with the background including the blackbody radiation from samples. On the other hand, a high-energy ion-implantation was found to be essential to the SiGe-OI substrate creation for the purpose of this study. Besides these, it was found through a series of luminescence experiments that the otherwise dissipative Auger recombination potentially competing with gain at an increased excitation density could be suppressed simply by implementing a SiGe/Si heterostructure. Less