Synthesis of Controlled III-Nitride Nanostructures

非技术描述：该项目旨在开发生产先进纳米级半导体材料的方法，称为量子点。这项研究工作采用了一种新的合成技术来制造这些量子点的集合体，从而更好地控制它们的大小、密度和分布。通过控制量子点的特性，它们的特性可以更接近理论预测和期望的性能。这些新材料旨在作为更高效的电子设备的有源元件，用于对国家经济产生积极影响的应用，包括固态照明、光伏、可见激光器、高温传感器和紫外线发光二极管。这项研究被纳入K-12教育和推广活动，也被纳入研究生和本科课程，以拓宽实验室以外的教育经验。该项目培养两名在先进半导体材料合成、材料表征、理论和器件技术等重要领域的研究生。技术描述：本项目的主要目标是探索在iii -氮化物半导体中生产单分散外延量子点的合成方法。具体来说，这个项目的努力包括：(i)使用量子尺寸控制的光电化学蚀刻合成量子点集成，（ii）在这些量子点上重新生长封盖层；（iii）用量子点有源层形成p-n结，（iv）表征量子点的光学特性以及由此产生的增益、自发发射和辐射效率。这些量子点系综具有可控的能量分布、密度和合金成分，有望在iii -氮化物半导体中实现强大的量子效应，通过调整iii -氮化物的能带结构来解决其各种局限性，以克服奥格复合、较长可见波长下较差的辐射效率、激光二极管的高阈值以及AlGaN紫外线发射器中不利的光偏振。

Nontechnical description: This project aims to develop methods for producing advanced nanometer-scale semiconductor materials, called quantum dots. The research effort employs a new synthesis technique to create ensembles of these quantum dots, enabling better control of their size, density and distribution. By controlling the quantum dots characteristics, their properties could be tuned closer to theoretical predictions and desired performance. These new materials are aimed to be used as active components in more efficient electronic devices for applications that positively impact the nation's economy, including solid-state lighting, photovoltaics, visible lasers, high temperature sensors, and ultra-violet light-emitting diodes. The research is incorporated into K-12 education and outreach activities, and is also integrated into graduate and undergraduate courses to broaden the educational experience beyond the laboratory. This project trains two graduate students in the highly important areas of advanced semiconductor materials synthesis, materials characterization, theory, and device technologies.Technical description: The principal goal of this project is to explore synthesis methods to produce monodisperse epitaxial quantum dots in III-Nitride semiconductors. Specifically, this project efforts include: (i) synthesis of quantum dot ensembles using quantum-sized-controlled photoelectrochemical etching, (ii) regrowth of capping layers on top of these quantum dots; (iii) forming p-n junctions with quantum dot active layers, and (iv) characterization of optical properties of the quantum dots and resulting gain, spontaneous emission, and radiative efficiency to established models. These quantum dot ensembles with controlled energy distribution, density, and alloy composition are expected to enable strong quantum effects in III-Nitride semiconductors, addressing various limitations in III-Nitrides by tailoring their bandstructure in order to overcome the Auger recombination, poor radiative efficiencies at longer visible wavelengths, high thresholds in laser diodes, and unfavorable optical polarization in AlGaN ultra-violet emitters.