SBIR Phase I: Engineered Ligands for Enhanced Stability of Colloidal Quantum Dots in Lighting and Display Applications

这项小型企业创新研究第一阶段项目旨在研究直接涂覆在发光二极管（LED）芯片上的基于量子点（QD）的降转换薄膜的可行性。集成高效QD材料作为LED下变频器，可以提高光输出的效率和质量；然而，现有的量子点薄膜缺乏片上应用的热稳定性。所提出的努力的目标是确定用无机配体集形成量子点的可行性，这些配体集产生具有大于80%的高光致发光（PL）外量子效率（EQEs）和温度稳定性的固态薄膜，使它们能够承受直接应用于led上。我们将表征溶液中帽交换量子点的有机含量和溶液量子产率（QY）。该项目将通过分析自旋涂层薄膜的光致发光EQE作为温度和时间的函数，确定这些帽交换量子点的光学特性是否能够直接应用于led。为了确定无机配体是否比现有的有机配体更稳定地随时间和温度变化，我们将在一组用我们的标准量子点制备的对照膜上进行全固态测试。这个项目的广泛影响/商业潜力是巨大的。这种片上方法的成功可能是量子点和LED下变频的“圣杯”，因为它为固态照明（SSL）和显示器提供了一种极其通用的、低成本的、基于LED的解决方案。除了较低的成本外，降低的复杂性使该解决方案成为照明集成商的一种真正的嵌入式方法，具有高显色指数和效率。由此带来的好处将推动高效、基于led的照明解决方案更快地被采用。由于超过20%的发电量用于照明应用，因此影响能源预算需求和减少该领域温室气体排放的机会是巨大的。额外的社会效益包括美国制造业基础的增长和对外国石油的依赖的减少。SSL市场规模估计为800亿美元，并且有一个引人注目的商业机会来解决目前的市场渗透障碍。此外，我们相信这种固态照明应用很容易转移到显示和电视市场的背光要求，量子点基薄膜也可以向下转换LED背光单元。显示市场应用代表着另外1000亿美元的机会。

This Small Business Innovation Research Phase I project proposes to investigate the feasibility of a quantum dot (QD)-based downconverting film coated directly on a light emitting diode (LED) chip. Integration of high-efficiency QD materials as LED downconverters can enhance the efficiency and quality of the light output; however, existing QD films lack the thermal stability for on-chip application. The objective of the proposed effort is to determine the feasibility of forming QDs with inorganic ligand sets that yield solid state films with high photoluminescent (PL) external quantum efficiencies (EQEs) of greater than 80% and temperature stability that would enable them to withstand direct application onto LEDs. We will characterize cap-exchanged QDs in solution for organic content and solution quantum yield (QY). The project will determine whether the optical properties of these cap-exchanged QDs would enable their direct application to LEDs, by analyzing the photoluminescent EQE of spin-coated films as a function of temperature and time. In order to determine whether the EQE is more stable as a function of time and temperature with the inorganic ligand sets than our current organic ligands, we will run all-solid state tests on a set of control films fabricated with our standard QDs.The broader impact/commercial potential of this project is significant. Success with this on-chip approach could be the "Holy Grail" for QDs, and for LED downconversion generally, as it provides a pathway for extremely versatile, low-cost, LED-based solutions for solid state lighting (SSL) and displays. In addition to lower cost, the reduced complexity makes this solution a true drop-in approach for lighting integrators, with high color rendering index and efficiency. These resulting benefits will drive much more rapid adoption of efficient, LED-based lighting solutions. With more than 20% of generated electricity consumed in the support of lighting applications, the opportunity to impact the demand-side of our energy budget and reduce greenhouse gases in this area is immense. Additional societal benefits include the growth of the U.S. manufacturing base and reduced dependence on foreign oil. The SSL market size is estimated to be $80 billion, and there is a compelling business opportunity to address the current barriers to market penetration. Additionally, we believe that this solid state lighting application readily transfers to backlight requirements of the display and television markets where quantum dot based films can also down-convert LED backlight units. The display market application represents an additional $100 billion opportunity.