The U.S. Department of Energy Office of Science has awarded seven new Phase I, three Phase II, and one Phase IIB Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) grants for projects targeting critical advances in solid-state lighting (SSL) technology. The seven new Phase I grants, originating from Fiscal Year (FY) 17 Releases 1 and 2, will explore the technical merit and commercial potential of different innovative concepts or technologies that are expected to contribute to the achievement of the price and performance goals described in DOE’s SSL R&D Plan, and will conclude in nine months. The four Phase II awards will conclude in 24 months and are designed to advance critical new technologies towards identified commercial SSL markets at the conclusion of the Phase II effort.
The SBIR-STTR program seeks to increase the participation of small businesses in federally sponsored innovative and novel research and development. To learn more about this program, visit http://science.energy.gov/sbir/.
The eleven SBIR-STTR grants directly related to SSL are briefly described below:
SBIR Recipient (Phase I): Luminit, LLC (Torrance, CA)
Title: Light Extraction System for OLED (LESO)
Summary: The proposed system is an advanced surface structure that increases light extraction in OLEDs using surface patterning in the interface between high- and low-refractive-index resins, to reduce the waveguide losses. The proposed LESO addresses DOE’s major SSL requirements for high-efficiency materials for OLEDs with significant commercial applications, including sheets that can be applied by OLED manufacturers. Increasing the light-extraction efficiency by a factor of two to four will increase overall efficiency from the current 20-40% up to 70%, enabling OLED lighting to achieve efficacies >190 lm/W. Luminit is ideally suited to develop this into a commercial product, since LESO will be compatible with the company’s current roll-to-roll and sheet-by-sheet production line of microstructured epoxy coatings. This manufacturing expertise will allow LESO to meet the DOE performance goals with an incremental cost of <$10/m2.
SBIR Recipient (Phase I): OLEDWorks, LLC (Rochester, NY)
Title: Ultra-thin, Curved, High Efficacy OLED Light Engine
Summary: This project will design and demonstrate an ultrathin, curved, high-efficacy OLED light engine that incorporates an OLED lighting panel on thin, flexible glass; a high-efficiency driver; and an easy-to-use mechanical/electrical connector that will offer luminaire designers a new, simple, and creative component to inspire and accelerate the commercial production of revolutionary designs with faster product-introduction cycles. The proposed curved light engine will expand on the rigid, flat OLED light engines currently available and will make it much easier and more economical to design and manufacture OLED lighting fixtures for the consumer market and the commercial architectural lighting industry. In Phase I, OLEDWorks will develop the ultrathin, bendable-glass, high-efficacy OLED panels and will specify or develop appropriate high-efficiency drivers for use in the light engine. A subcontractor luminaire manufacturer will design the light engine together with a prototype consumer fixture and commercial luminaire for use with the light engine.
SBIR Recipient (Phase I): Pixelligent Technologies (Baltimore, MD)
Title: Light Extraction for OLED Lighting with 3-D Gradient Index
Summary: The mismatch between the refractive indices (RI) of the active layer, transparent conductive anode layer, indium tin oxide, and substrate is a well-known major cause of light-extraction inefficiency in OLEDs. By incorporating any high-RI internal light-extraction (ILE) layer that addresses this problem, the efficacy and lifetime of OLED devices can dramatically improve. This project will explore the application of a novel and unique three-dimensional gradient index (GRIN) layer for this purpose. Using such a unique structure, OLEDs could be produced that achieve the theoretical maximum extraction efficiency. Furthermore, such a device would be capable of directing light to where it’s most needed, while maintaining the desired “off-state” appearance of an OLED when fabricated into a practical luminaire. In Phase I of the project, Pixelligent will demonstrate the performance and possible manufacturing method by using a laboratory-scale inkjet printer to prepare a functional three-dimensional GRIN layer for incorporation into an OLED test coupon by OLEDWorks.
SBIR Recipient (Phase I): Lumisyn, LLC (Rochester, NY)
Title: High Performance Nanocrystals in Silicones
Summary: This project seeks to form unique nanocrystal-based silicone films that have high quantum efficiencies and low optical scattering losses, and that will maintain these critical properties under LED operation and with optically dense films. Novel nanocrystal surface-region materials will be synthesized, analyzed for performance, and then optimized accordingly in order to enable maximum efficiency with minimal scattering loss for the proposed silicone-based films. The main goal for the Phase I effort is to develop stable, silicone-based films that will demonstrate high-performance optical properties and will maintain these properties under the harsh operating conditions of production LEDs. The resulting nanocrystal-based silicone films can then be placed directly on blue LEDs without losing efficiency. Used in conjunction with phosphor-converted LEDs containing conventional green-yellow-emitting bulk phosphors, the resulting phosphor blends can be used to create warm-white LEDs with an increase in white LED efficacy of up to a factor of 1.3, while enabling quality white light with high color rendering. By adding green- and yellow-emitting nanocrystals to the silicone films, further LED system efficacy gains can be made while also enabling custom light sources to be created.
SBIR Recipient (Phase I): OLEDWorks, LLC (Rochester, NY)
Title: OLED Lighting Substrate and Encapsulation System for Breakthrough Cost Reductions
Summary: This project seeks to develop a novel substrate and encapsulation process that will significantly reduce the cost of OLED lighting. The ways cost will be reduced include a) reducing the cost of the substrate by eliminating the need to pattern the anode layer; b) reducing the OLED deposition capital equipment cost and process operation cost by cutting the number of different masks in half, with the potential to eliminate the masks altogether; and c) increasing the lit area of the panel to get significantly more light per panel. A key element of the proposed cost reductions depends on the application of a relatively new electrical attachment technology to form a hermetic seal around the OLED lighting area. This system will use a robotically controlled production-scale process that OLEDWorks has already used to develop processes and select materials for electrical attachment. In addition to these proven processes, the technique will be further developed to form hermetic encapsulation on a simpler substrate, making it possible to produce a narrower unlit width around the panels. During Phase I, the hermetic sealing will be demonstrated on an increasingly challenging set of formats, from simple systems demonstrating the component parts, to the fully integrated OLED system. The final result will be a complete proof-of-principle for this novel substrate and encapsulation system, demonstrating the proposed reduction in manufacturing cost and thereby reducing a significant barrier to commercial OLED sales for general illumination applications. In Phase II, the technology will be scaled up, and new commercial products using this technology will be launched.
SBIR Recipient (Phase I): SC Solutions Inc. (Sunnyvale, CA)
Title: Radiation-assisted MOCVD Heating for Improved Within-wafer Temperature Uniformity in LED Manufacturing
Summary: This project seeks to demonstrate the feasibility of an innovative control technology for improved within-wafer temperature uniformity in the metal-organic chemical vapor deposition (MOCVD) process that’s most commonly used to produce commercial multi-quantum-well LEDs. The proposed technology promises to substantially reduce the need for “binning” in LED manufacturing – a common production challenge that represents additional cost and complexity, including reduced wafer yield and less-than-ideal emission properties of phosphor-converted LEDs. These challenges are believed to hinder more-widespread acceptance of LED products for energy-efficient building-illumination applications. SC Solutions will address this challenge by employing radiant heating from the top of the wafer, with a heat-flux profile shaped using a specially designed mask. The heater will be located beyond the susceptor edge within the MOCVD or tool and will be controlled in conjunction with the susceptor heaters, using an integrated control architecture. This approach is projected to reduce within-wafer non-uniformity by 90% or more.
STTR Recipient (Phase I): MicroLink Devices Inc. (Niles, IL) with National Renewable Energy Laboratory (Golden, CO)
Title: AlxIn1-xP LEDs with II-VI Cladding Layers for Efficient Red and Amber Emission
Summary: This project will seek to improve the performance of phosphide-based red and amber LEDs – which are used in certain popular SSL designs – by engineering the composition and combination of semiconductor materials to overcome the fundamental loss mechanisms known to limit performance. The proposed approach builds on the team’s longstanding efforts using similar materials to advance high-efficiency multijunction solar-cell technologies. The main objective is to improve the performance of red and amber LEDs by implementing an AlxIn1-xP -based active region in combination with an advantageous electron-cladding layer based on a higher-bandgap II-VI semiconductor alloy. This approach is projected to mitigate internal and external loss mechanisms in a significant way, thereby increasing efficacy in a stable and cost-effective manner. Innovative crosscutting technology that was developed under DOE-supported solar programs will be used in the design and fabrication of phosphide-based LEDs for eventual use in high-performance SSL systems. The approach is proposed to be the most significant improvement in the efficiency of red and amber LEDs in decades, and to reduce market adoption risk by using existing device designs and manufacturing processes.
SBIR Recipient (Phase II): Lumisyn, LLC (Rochester, NY)
Title: Tunable nanocrystal-based phosphors with reduced spectral widths
Summary: Colloidal nanocrystals have been promoted as a viable alternative for warm-white LED light sources that employ spectrally wide red-emitting bulk phosphors. However, these nanocrystals continue to exhibit unwanted quenching of the quantum efficiency and increases in their spectral width at the elevated temperatures and excitation levels characteristic of high-power LEDs. Lumisyn has successfully created a novel class of high-efficiency, nontoxic nanocrystals that overcome many of the longstanding problems of other alternatives. Before successfully commercializing these materials, their efficiency must be further improved and their emission spectral width minimized. By targeted synthetic/compositional work in combination with appropriate optical and material characterization of the nanocrystals, Lumisyn will further refine a model of the factors contributing to high-efficiency under both ambient and adverse (high-temperature and high-excitation-flux) LED operating conditions. Additionally, the company will identify compositional factors that lead to unwanted loss of nanocrystal efficiency, and will also explore synthetic and compositional changes to further reduce the spectral width of the orange- and red-emitting nanocrystals. Targeted improvements include reduction of the spectral width by ~20% and improvement in overall LED efficacy by up to a factor of 1.4, while simultaneously improving color quality. These performance improvements will reduce general-lighting life-cycle costs, improve lighting quality, and reduce carbon footprint.
SBIR Recipient (Phase II): PhosphorTech Corporation (Kennesaw, GA)
Title: Hybrid Down-Converting Structures for Solid State Lighting
Summary: Achieving higher luminous efficacy in phosphor-converted LEDs requires breakthroughs in downconverting materials that provide high conversion efficiency, tunable narrow-bandwidth emission, and good temperature/chemical stability. To achieve these goals, PhosphorTech and its partners propose the development of high-performance hybrid inorganic downconverting (HID) material systems for high-brightness LED applications. While conventional bulk phosphors are currently the dominant downconverters used in high-power SSL applications, their performance is limited by intrinsic properties such as high-scattering cross-sections and large emission bandwidth. By designing a complete inorganic hybrid system as proposed, PhosphorTech believes that the new HID materials will outperform bulk phosphors, nanocrystals, and conventional quantum dots, and that they’ll enable a new generation of SSL devices with high luminous efficacies, high color and thermal stability, and spectral efficiency near the theoretical maximum luminous efficacy of radiation, as a result of their color tunability and narrow bandwidths (FWHM < 30nm).
SBIR Recipient (Phase II): Lucent Optics Inc. (Sacramento, CA)
Title: Ultra-Thin Flexible LED Lighting Panel
Summary: This project proposes to develop and offer for sale a novel wide-area luminaire technology that enables efficient and cost-effective combination of high-brightness LEDs and flexible light-guiding films. The use of a light-guiding film allows for creating a large-area distributed light source that emits soft and uniform glow without the glare typically associated with individual LEDs. This technology will dramatically reduce the material intensity, cost, energy consumption, and environmental impact of lighting fixtures and enable the eventual manufacture of ultrathin, flexible luminaires. Uniquely, the technology combines the low cost, high efficiency, and manufacturing maturity of inorganic LED technology with the flexible and ultrathin form and design flexibility characteristic of OLEDs. In Phase I, the feasibility of the technology was demonstrated, and Lucent Optics produced a number of functional prototypes of flexible lighting panels that met all of the performance targets – in particular, panel thicknesses below 1mm, bend radii below 50mm, brightness uniformity of 85%, and peak luminance from 5,000 cd/m2 to 20,000 cd/m2. During Phase II, Lucent Optics will scale the technology up to the size of real-world lighting fixtures and focus on further improving the overall panel performance and end-use product development. With the subsequent commercialization efforts, the company plans to create and market a wide array of ultra-low-cost LED luminaires that have innovative shapes and attractive designs and could dramatically expedite the conversion of conventional lighting to SSL.
SBIR Recipient (Phase IIB): Pixelligent Technologies, LLC (Baltimore, MD)
Title: Advanced Light Extraction Material for OLED Lighting
Summary: The mismatch between the refractive indices among the active layer, transparent conductive anode layer, indium tin oxide, and substrate is a major root cause of light loss in OLEDs. Incorporating any internal light-extraction structures that address this root cause can dramatically improve the efficacy and lifetime of the OLED device. Pixelligent will team with OLEDWorks to demonstrate a cost-effective high-refractive-index nanocomposite formulation that will function as a key part of an internal light-extraction structure. This structure will be fully compatible with OLED device manufacturing processes and operation conditions and will be able to expedite the commercialization of white OLED lighting.