SBIR Phase I: Integration of Langmuir-Blodgett Quantum Dot Films Into Optoelectronic Device Heterostructures

这项名为“朗缪尔-布洛杰特量子点薄膜在光电子器件异质结构中的集成”的小型企业创新研究第一阶段项目将推动胶体半导体量子点(SQD)在无机半导体光电子器件中的应用。纳米结构在II型氮化物发光二极管从紫色到蓝绿色的高效率运行中起着至关重要的作用。Dot Metrics Technologies拥有新颖的知识产权，通过集成II-VI Sqd层将III-氮化物LED颜色扩展到深绿色。DMT等人已经证明了具有低壁塞效率的电致发光器件。到目前为止，用于沉积量子阱的滴注和旋转铸造方法导致了不均匀的SQD层，降低了通过异质结构的垂直电子传输的均匀性。在这个项目中，标准的朗缪尔-布洛杰特单层薄膜沉积技术将被用来沉积单层量子阱薄膜。通过这种方式，Sqd有源层的厚度将与III-氮化物LED中的量子阱厚度相同。利用分子束外延技术(MBE)封装量子阱形成器件异质结构，并制作发光二极管并进行测试，该项目的广泛影响是显著的。接近人眼反应峰值的深绿色光是“白光”和多色显示器的重要组成部分。通常，深绿色是通过有损耗的荧光粉下转换产生的。该项目将通过QQD的直流电抽运产生更高效率的深绿色。由此产生的设备将非常畅销；因此，这项工作完成后将吸引来自非SBIR来源的进一步资金。此外，深绿色的直接电气控制允许更好地控制主观颜色质量，从而实现更高质量的照明和显示，并节省能源。SQD与传统半导体外延的集成本身就是一个很有市场的过程，可能适用于其他类型的光电子器件，如探测器或太阳能电池。到目前为止，DMT已经执行了另外四个SBIR项目，虽然还没有产品商业化，但与这项工作有关的许多出版物证明，已经取得了重大的技术进步

This Small Business Innovation Research Phase I project, entitled "Integration of Langmuir- Blodgett quantum dot films into optoelectronic device heterostructures", will drive incorporation of colloidal semiconductor quantum dots (SQD) into inorganic semiconductor optoelectronic devices. Nanostructure plays a critical role in high efficiency operation of IIInitride light emitting diodes over a range from violet to blue-green. Dot Metrics Technologies has novel intellectual property to extend III-nitride LED color to the deep green through integration of II-VI SQD layers. Electroluminescent devices with low wall plug efficiency have been demonstrated by DMT and others. Drop casting and spin casting methods used so far to deposit SQD result in non-uniform layers of SQDs, degrading uniformity of vertical electronic transport through the heterostructures. In this project, standard Langmuir-Blodgett monolayer film deposition techniques will be employed to deposit single layers of SQD. In this way, SQD active layers will be on the order of the same thickness as quantum wells in III-nitride LEDs. Molecular beam epitaxy (MBE) will be used to encapsulate SQD to form device heterostructures, and light emitting diodes will be fabricated and tested.The broader impact of this project is significant. Deep green light, near the human eye response peak, is an essential component of "white light" and multicolor displays. Typically, deep green is generated through lossy phosphor down-conversion. This project will result in higher efficiency generation of deep green through direct electrical pumping of SQD. Resulting devices will be highly marketable; thus, the work will attract further funding from non-SBIR sources upon completion. Also, direct electrical control of deep green allows better control of subjective color quality, resulting in higher quality lighting and displays, and also energy savings. Integration of SQD with traditional semiconductor epitaxy is itself a marketable process, potentially applicable to other types of optoelectronic devices such as detectors or solar cells. DMT has executed four other SBIR projects to date, and while no products have yet been commercialized, significant technical progress has been made as evidenced by the numerous publications associated with this work