SBIR Phase I: Ultra High Efficiency Top-emitting Quantum Dot light-emitting Display Incorporating Microlens Array

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.