SBIR Phase I: Highly Efficient, Long Lifetime, and Inexpensive Nanocrystal Light Emitting Diodes (LEDs)

这个小型企业技术转移（STTR）一期项目将探索基于半导体纳米晶体的高效、长寿命和廉价的发光二极管（led）。半导体纳米晶体led的制造技术与用于商业用途的聚合物led的制造技术非常相似。因此，纳米晶体led的商业潜力主要取决于纳米晶体的光学质量。本项目设计采用两项最新技术，生产出具有极高发射效率和优异化学和热稳定性的半导体纳米晶体。树突配体技术为纳米晶体提供了抗化学处理和器件运行中的热效应的优异稳定性。利用亮点概念合成的纳米晶体具有前所未有的光学质量，约80%的光致发光量子产率，23-27 nm的发射全峰宽为半最大值，450-700 nm的发射窗口可调。有了这些高光学质量和高可加工性的半导体纳米晶体，新一代半导体纳米晶体led有可能具有至少与聚合物led兼容的性能，但具有低成本和连续可调谐和窄发射轮廓。聚合物led和纳米晶体led的商业潜力将在很大程度上取决于器件的寿命和成本。纳米晶体led几乎具有聚合物led的所有优点，但具有更大的可调谐性和更窄的发射轮廓。在这个阶段，聚合物led寿命的商业标准是几千小时左右。该项目的商业目标是将纳米晶体led的性能提高到至少与聚合物led的水平。这些设备是在便携式电子设备上使用的，例如便携式计算机和蜂窝电话。

This Small Business Technology Transfer (STTR) Phase I project will explore high efficient, long lifetime and inexpensive light emitting diodes (LEDs) based on semiconductor nanocrystals. The fabrication technology of the semiconductor nanocrystal LEDs is very much similar to the one used for the fabrication of polymer LEDs for commercial purposes. As a result, the commercial potential of the nanocrystal LEDs relays mainly on the optical quality of the nanocrystals. This project design adopts two recent technologies, which yields semiconductor nanocrystals with extremely high emission efficiency and exceptional chemical and thermal stability. The dendron ligand technology provides nanocrystals with exceptional stability against the chemical processing and the thermal effect in the operation of the devices. The nanocrystals synthesized using the bright point concept produces unprecedented optical quality, about 80 percent photoluminescence quantum yield, 23-27 nm emission full peak width at half maximum, and tunable emission window from 450-700 nm. With those high optical quality and highly processable semiconductor nanocrystals, it is possible that a new generation of semiconductor nanocrystal LEDs, which have at least compatible performance to the polymer LEDs, but with low cost and continuous tunable and narrow emission profile.The commercial potential of the polymer LEDs and nanocrystal LEDs will highly depend on the lifetime and the cost of the devices. Nanocrystal LEDs possess nearly all of the advantages of polymer LEDs, but with significantly more tunable and narrow emission profile. At this stage, the commercial standard for the lifetime of the polymer LEDs is around several thousand hours. The commercial goal this project is to boost the performance of the nanocrystal LEDs to at least the level of that of polymer LEDs. The usage of those devices is on portable electronic devices, such as portable computer and cellular telephone.