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

这个小型企业创新研究(SBIR)第二阶段项目将把基于半导体纳米晶体(NanoLED)的发光二极管的性能提升到与有机/聚合物发光二极管(OLED)相同的水平。这一第二阶段计划的目标纳米LED的关键参数是2000小时的工作寿命，高于200 cd/m2的亮度，以及0.5-2%的外部量子效率。第二阶段计划将通过对器件中纳米晶体薄层的独特设计来提高纳米LED的性能。这种设计使所有纳米晶体的配体能够在粒子内和粒子内交联，从而产生高性能器件所需的热稳定性纳米晶体薄膜。与传统的长脂肪族配体不同，三维交联型配体较短，具有准共轭电子结构。这一选择旨在显著改善纳米LED中的电荷注入和电荷传输。将使用的新型纳米晶体将减少文献中所确定的致密堆积的纳米晶体薄膜中的重吸收和能量转移。在国家机构的坚定支持和与主流行业的广泛合作下，该公司有望在五年内将这项技术在显示和照明行业商业化。纳米LED的商业潜力是巨大的。纳米发光二极管几乎拥有有机发光二极管的所有优点，但具有容易调节和窄的发射轮廓。有机发光二极管目前正被用于积极的商业开发。第二阶段的商业目标是将纳米LED的性能提高到至少与聚合物LED相同的水平，聚合物LED是OLED设备的低端产品。第一代纳米LED将用于便携式电子设备。当纳米LED的寿命延长到十年以上时，它们将被用于其他显示技术和照明行业。纳米LED总有一天会改变我们看待世界的方式。根据行业估计，包括纳米LED在内的柔性LED的短期市场在2005年将达到50亿美元。在它们适应平板图形和照明应用的主流之后，市场规模将至少达到数百亿美元。

This Small Business Innovation Research (SBIR) Phase II project will advance the performance of light emitting diodes based on semiconductor nanocrystals (NanoLEDs) to the same level of that of organic/polymer light emitting diodes (OLEDs). The key parameters of NanoLEDs targeted for this Phase-II program are 2000 hours operation lifetime, above 200 Cd/m2 brightness, and 0.5-2% external quantum efficiency. The Phase-II program will improve the performance of the NanoLEDs through a unique design of the nanocrystal thin layer in the devices. This design enables the ligands of all nanocrystals to be inter- and intra-particle cross-linked, which results in the thermally stable nanocrystal thin films required for high performance devices. The three dimensionally cross-linked ligands are short and have quasi-conjugated electronic structures, instead of the traditional long aliphatic ligands. This choice aims to dramatically improve the charge injection and charge transport in the NanoLEDs. New types of nanocrystals to be used will diminish the re-absorption and energy transfer in the densely packed nanocrystal thin films identified in literature. With the committed support from a state agency and extensive collaboration with mainstream industry it is expected to commercialize this technology in the display and lighting industry within five years. The commercial potential of NanoLEDs is enormous. NanoLEDs possess nearly all of the advantages of OLEDs, but with readily tunable and narrow emission profiles. OLEDs are currently being used in active commercial development. The commercial goal in the Phase-II is to boost the performance of the NanoLEDs to at least the same level of that of the polymer LEDs, the low end of OLED devices. The first generation of NanoLEDs will be used in portable electronic devices. When the lifetime of NanoLEDs is extended over ten years, they will be used for other display technologies and in the lighting industry. NanoLEDs will one day change the way we see the world. Based on industry estimation, the near-term market for flexible LEDs, including NanoLEDs, will be $5 billion in 2005. After they are adapted to the mainstream of the flat panel graphics and lighting applications, the market size is going to be at least tens of billions.