UV Pumped, Quantum Dot Color Conversion Micro-LED Displays Manufacturing Readiness
Dr. Nag Patibandla, Vice President, Advanced Deposition Products, Office of the CTO at Applied Materials, Inc
Presentation Abstract
Applied Materials, Inc has developed a novel micro-LED display architecture together with commercial-scale process and equipment for micro-LED display manufacturing. This architecture consists of UV-A micro-LEDs, 4-subpixel layout, Cd-free QD formulations (of all three primary colors R/G/B), and a UV blocker atop. Several 1.37” smart-watch active-matrix display prototypes were assembled and tested. Our Cd-free QDs and the matrix materials are quite stable under the UV excitation used in our display, as verified by exposing them to display operation conditions but also under a high-flux accelerated test method and temperature. The emission properties of R/G/B QDs were further optimized, paving a path to achieve 100% DCI-P3 color space coverage. Our display also shows a high uniform Lambertian emission pattern with minimal color shift at all viewing angles. We have developed a production scalable micro-LED die transfer processes and corresponding equipment using which we have achieved > Four 9s transfer yields. To precisely deposit and massively process R/G/B QD inks into respective sub-pixel well array of our display, we have developed a production-scale process and print-platform details of which will be highlighted in the presentation. To address pixel-yield loss from die-transfer, we have implemented a simplified sub-pixel repair method that allows for ink-jetting of QD formulation into defective subpixel. This approach results in over a 10-fold yield improvement. In this presentation, we will report the readiness of key processes, materials, and equipment scalable towards commercialization.
Dr. Nag Patibandla, Vice President, Advanced Deposition Products, Office of the CTO at Applied Materials, Inc
Nag Patibandla is the Vice President for Advanced Deposition Products in the Office of the CTO at Applied Materials, Inc. He manages a number of emerging technology programs aimed at developing new products, validating innovation, defining product architecture and business strategy, and engaging partners. Nag’s current areas of interest include: Micro-LED displays, III-Nitride devices, superconducting materials, optical and quantum films, 3D Printing, CMP pads, deposition processes (MOCVD, PVD), etc. His expertise is in identifying growth opportunities and developing strategic plans for product development in various emerging technologies and semiconductor-adjacent areas. In addition,
Nag oversees Applied’s government/external funding strategy, development, and programs in various core and adjacent areas of business.Nag joined Applied in 2008. Since, he has helped establish programs in various new technology areas and has established an infrastructure to secure and administer external/government funding for growth programs. Nag has over 25 years of experience in industry, academia, and government, with an extensive R&D background in semiconductors, solid state lighting, photovoltaics, batteries, fuel cells, high temperature superconductivity, and related technologies. Before joining Applied, Nag was the Director of Center of Future Energy Systems at Rensselaer Polytechnic in Troy, NY. Prior to that, he worked in New York State government and at the General Electric Global R&D Center.
Nag received his Ph.D. in Materials Science and Engineering and a Master’s degree in Mechanics and Materials Science from Rutgers University, NJ, having first completed his bachelor’s degree in Metallurgical Engineering at the National Institute of Technology, Warangal (formerly Regional Engineering College) in India. He has authored/co-authored over 300 publications that include peer reviewed papers and patent applications in various areas of materials engineering.
In recognition of his professional achievements, the Board of Governors and Management of National Institute of Technology, Warangal, India bestowed Distinguished Alumni Professional Achievement Award (2020). Other notable recognitions include CHP Champion by the U.S. Combined Heat and Power Association (2003), Energy Professional of the Year by the New York Chapter of Association of Energy Engineers (2007), Rensselaer Polytechnic Institute Trustee “Faculty Achievement” recognition (2007), Applied Materials President’s Quality Award (2011) and the Best Patents of Applied Materials award (2018). Dr. Patibandla currently serves a four-year term as a Member of Emerging Technology Technical Advisory Committee, U.S. Dept of Commerce (2020-24), and had previously served on numerous U.S. Dept. of Energy Committees and various U.S. National Laboratory External Review Panels.