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

这个小企业创新研究（SBIR）二期项目将把基于半导体纳米晶体（NanoLEDs）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。第二阶段计划的关键参数是2000小时的工作寿命，200 Cd/m2以上的亮度，0.5-2%的外量子效率。第二阶段计划将通过在器件中独特的纳米晶体薄层设计来提高纳米oled的性能。该设计使所有纳米晶体的配体能够在粒子间和粒子内交联，从而产生高性能器件所需的热稳定纳米晶体薄膜。三维交联配体较短，具有准共轭电子结构，取代了传统的长脂肪族配体。这种选择旨在显著改善纳米oled中的电荷注入和电荷输运。新型纳米晶体将减少文献中发现的致密纳米晶体薄膜中的重吸收和能量转移。在国家机构的大力支持和与主流行业的广泛合作下，预计该技术将在五年内在显示和照明行业实现商业化。纳米oled的商业潜力是巨大的。纳米oled几乎拥有oled的所有优点，但具有易于调谐和窄发射轮廓。oled目前正积极用于商业开发。第二阶段的商业目标是将纳米OLED的性能提高到至少与聚合物led相同的水平，聚合物led是OLED器件的低端。第一代纳米oled将用于便携式电子设备。当纳米oled的寿命延长到10年以上时，它们将用于其他显示技术和照明行业。纳米oled总有一天会改变我们看世界的方式。据业界估计，2005年柔性发光二极管（包括纳米发光二极管）的近期市场规模将达到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。

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.