NER: Initiative on novel nanostructures and nanodevices based on semiconductor epitaxial growth

我们想为纳米结构和纳米器件的设计、生长和表征方面的一流努力提出一个NER倡议。我们提案的第一部分涉及量子阱（QW）点的设计，生长和表征。我们建议通过在InGaAs/GaAs量子阱顶部生长InP应力源来生长这种新结构。InP应力源通过局部应变产生约束势来调节QW带隙。由于GaAs势垒和InP层之间的晶格不匹配，应变诱导的2D - 3D转变形成了InP岛。我们将通过光致发光，激发光谱和时间分辨泵浦探针技术来表征结构。我们将根据实验结果对结构进行优化。我们计划研究利用这种结构产生远红外线和太赫兹波的可能性。我们还将利用外延生长的最新进展，基于一些新的异质结构开发革命性的新型半导体激光器和放大器。这些结构包括ii型量子阱，由具有正负波段偏移的材料层交替组成的异质结构；量子点（QD’s）具有间接带隙材料制成的屏障。在这些结构中，重组时间可以设计在一个很宽的范围内（高达三个数量级）。由于复合时间长，存储在上层激光能级的能量也可以增加，最多可达两三个数量级。因此，可以在调q激光器或主振荡器/功率放大器方案中产生具有高峰值功率的纳秒和亚纳秒脉冲。另外，具有极低噪声和串扰的半导体激光放大器也成为可能。此外，通过减少量子点中非激光能级的复合，可以实现真正的温度无关的激光操作和窄线宽。提出的研究将导致基于量子阱和量子势垒点的未来太赫兹发射器和探测器的发展，以建立一个紧凑的传感器阵列，用于化学和生物传感和生物医学应用。此外，所提出的研究的影响包括全新的半导体激光器和放大器，其脉冲功率和稳定增益特性接近稀土掺杂激光器，但具有半导体激光器固有的效率，紧凑性和可靠性。拟议中的项目将被用作大学和工业伙伴之间合作的典范。它将为未来的NSF目标奠定基础。此外，我们将雇用一名少数民族学生，并在光学技术跨学科中心招募和保留少数民族学生。

We would like to propose a NER initiative for the first-class effort on designs, growth, and characterization of nanostructures and nanodevices. The first part of our proposal deals with design, growth, and characterization of quantum-well (QW) dots. We propose to grow this novel structure by growing InP stressors on the top of the InGaAs/GaAs QW. The InP stressors modulate the QW band-gap with local strain generating confinement potential. InP islands are formed due to a strain-induced 2D 3D transition, taking place, because of lattice misfit between the GaAs barrier and InP layer. We will characterize the structure by photoluminescence, excitation spectrum, and time-resolved pump-probe technique. We will optimize the structure following our experimental results. We plan to investigate the possibility of using the structure for generating far-IR and THz waves.We will also develop revolutionarily new semiconductor lasers and amplifiers based on a few novel heterostructures, using the latest advances in the epitaxial growth. These structures include type-II QW's the heterostructures consisting of alternating layers of materials with positive and negative band offsets; and quantum dots (QD's) with barriers made of indirect band gap materials. In these structures the recombination time can be engineered with a broad (up to three orders of magnitude) range. Owing to the long recombination time, the amount of the energy stored on the upper laser level can also be increased, up to two three orders of magnitude. Thus nanosecond and sub-nanosecond pulses with high peak powers can be produced in either Q-switched laser or master oscillator/power amplifier schemes. Separately, semiconductor laser amplifier with extremely low noise and cross-talk also become feasible. Furthermore, by reducing the recombination via non-lasing levels in QD's one can achieve truly temperature-independent laser operation and narrow line width.The proposed research will lead to development of the future THz emitters and detectors based on the quantum-well and quantum-barrier dots to build a compact sensor array for chemical & biological sensing and biomedical applications. Furthermore, the impact of the proposed research includes the radically-new type of the semiconductor lasers and amplifiers with pulsed-power and stabilized-gain characteristics approaching those of the rare-earth-doped lasers, but with the efficiency, compactness and reliability, that are inherent of semiconductor lasers.The proposed project will be used as a model for collaboration between universities and industrial partners. It will lay foundation for a future NSF GOALI. Furthermore, we will employ a minority student as well as recruit & retain minority students within the interdisciplinary center of optical technologies.