SBIR-STTR Award

This Small Business Innovation Research Phase I project seeks to demonstrate ultra high efficiency quantum dot light-emitting diodes (QD-LEDs) using a top-emitting structure and micro-lens array for display applications. Two key challenges will be addressed. First, a novel top-emitting structure will be explored based on the previous efficient bottom-emitting QD-LEDs. Use of top-emitting structure removes light trapped through the wave-guide mode within the glass substrate, which improves light out-coupling. A micro-lens array will be applied on top of the QD-LEDs to further enhance the light extraction. The project will focus on a number of innovative approaches. Micro-lens arrays will be fabricated using a novel stamp printing method. A small size micro-lens along with a top-emitting structure will minimize the pixel blurring effect induced by the conventional out-coupling micro-lens. Secondly, high refractive index material will be used to fabricate a micro-lens to match the refractive index of the transparent electrode, hence improving light extraction efficiency. The broader impact/commercial potential of this project lies is to enable the commercialization of QD-LED displays, solid-state lighting and other applications. QD-LEDs provide intrinsically higher color purity compared to LCD or organic light-emitting diode (OLED) technology and are suitable for display applications. However, current QD-LED solutions suffer from lower efficiency compared to LCD and OLED. The company?s innovative nanomaterials and device architecture has enabled very efficient bottom-emitting QD-LEDs with high external quantum efficiency. Additionally, the multi-layer structure in the company?s QD-LED are deposited through solution processing, which reduces the cost significantly. It is expected that a better performing and substantially less expensive QD-LED will quickly gain considerable market share in a $60B market that ships over 1.5B units a year

This Small Business Innovation Research (SBIR) Phase II project aims to further enhance the efficiency and lifetime of quantum dot light emitting diodes (QD-LEDs) used for displays. An active matrix QD-LED prototype display will be demonstrated using solution processing. The lifetime of QD-LED will be extended by determining degradation mechanisms, and development of new materials, modified device processing and encapsulation techniques. The effects of charge imbalance and light trapping on the efficiency of QD-LED will be determined and optimized. External quantum efficiencies will exceed 18%. Lifetimes of QD-LEDs exceeding 10,000 hours for all three primary colors will be demonstrated, which meets the requirement for mobile display applications.The broader impact/commercial potential of this project will be a demonstration that quantum dot light-emitting diodes (QD-LEDs) have the commercial advantages of high efficiencies and long lifetimes. QD-LED will be welcomed by the display industry which is now desperately searching for next generation technologies. The demonstration of an active matrix QD-LED display prototype with a solution printing process will be a critical step towards the commercialization. The systematic investigation of technical details involved in the printing process of active matrix QD-LEDs will enable the construction of a pilot facility and eventual mass production. The simple architecture and solution fabrication process will provide significant cost advantages over conventional processes.