A Study of Rare-Earth Doped Semiconductors and Novel Laser Structures

该奖项旨在支持稀土掺杂半导体，以实现新型光电器件和光源的可能性。稀土相关4f发射的波长实际上不依赖于宿主晶体的带隙能量，并且不受温度变化的影响。然而，激光器的增益不高，稀土掺杂和激发过程还不清楚。我们提出了一个系统的研究GaAs和inp基半导体-主要是GaAs和InGaAsP -在MBE期间被Er和Yb注入。实验将包括共振和非共振激发的时间分辨发光，电导和导纳光谱来表征深能级，低场和高场输运和反射率测量。期望这些实验将提高对掺杂过程、材料辐射和非辐射性质变化的基本认识。以及稀土相关跃迁的时间特征。后者对于高速脉冲激光器的设计尤为重要。PI还提出了在几种新型激光结构中使用稀土掺杂材料。在第一种活性介质中，选择性掺杂具有窄稀土掺杂井的MQW。第二种方法是利用雪崩载流子的级联与稀土跃迁能发生共振，从而通过碰撞激发产生较大的非平衡分布。

This award is to support rare-earth doping of semiconductors for the possibility of realizing novel types of optoelectronic devices and sources. The wavelength of the rare-earth related 4f emissions practically does not depend on the bandgap energy of the host crystal and is immune to temperature variations. However, the gain of the lasers is not high and the rare- earth doping and excitation process is not clearly understood. We propose a systematic investigation of GaAs and InP-based semiconductors - mainly GaAs and InGaAsP - doped during MBE by Er and by implantation of Yb. The experiments will include time-resolved luminescence with both resonant and non-resonant excitation, conductance and admittance spectroscopy to characterize deep levels, low and high field transport and reflectance measurements. It is expected that these experiments will improve the basic understanding of the doping process, changes in the material radiative and non-radiative properties, and the temporal characteristics of the rare-earth related transitions. The latter are particularly important for the design of high-speed pulsed lasers. The PI also proposes the use of rare-earth doped materials in a couple of novel laser structures. In the first the active medium is a selectively doped MQW with narrow rare-earth doped wells. In the second, a cascade of avalanching carriers is made to resonate with the rare-earth transition energy, thereby causing a large non- equilibrium distribution through collision excitation.