Lars Samuelson
Novel approaches towards sub-µm scale InGaN microLEDs for AR-applications
SUSTech, China; Lund University and Hexagem AB, Sweden
Abstract
For miniLEDs and large-sized microLEDs, Blue and Green is made from III-Nitrides, while Red is made from AlGaInP/GaAs. For pixel sizes approaching 10 µm, and below, top-down processing of AlGaInP wafers lead to un-acceptable defects killing the efficiencies. Although the III-Nitrides are less prone to defects and carrier diffusion, efficient Red is still extremely hard to achieve, due to large lattice-mismatch between InGaN and the GaN substrate. I will here present a survey of approaches to enable all RGB-colors by III-Nitrides also for extemely small-pixel microLEDs. I will describe how we replace the GaN substrate with relaxed InGaN, thus reducing the lattice mismatch. By the use of bottom-up crystal growth, from seeding of GaN nanowires, we create extended platelets of InGaN, freely separated from the GaN substrate and the growth mask. On top of these platelets we form the entire micro/nanoLED structure having IQE-values typically 60%, also for device sizes below 1 µm, i.e. pixel-sizes as required for advanced AR (Augmented Reality) applications.
Biography
Lars Samuelson received his PhD in Physics in Lund, 1977, followed by a Post-doc at IBM Research Centre, California. In 1986 Professor in Physics, Gothenburg and in 1988 Professor at Physics Department in Lund. In 1988 he initiated a Nanoscience Centre, NanoLund, today with more than 400 researchers. Since 2021, he is Chair Professor at Southern University of Science and Technology (SUSTech), in Shenzhen, China, and Director of the Institute of Nanoscience and Applications (INA).
He is a member of the Royal Swedish Academy of Sciences, of the Royal Swedish Academy of Engineering Sciences and Foreign Member of the Chinese Academy of Sciences, CAS. Lars Samuelson is the founder and chief scientist of four start-ups working on the commercialization of nanowire and nanomaterial technologies, in QuNano AB, GLO AB, Sol Voltaics AB and Hexagem AB. Samuelson is the author of well over 700 articles with h-index 92 at Web-of-Science (h-index 112 by Google Scholar) and listed among the 1% most highly cited researchers by Web-of-Science.
Kristiaan Neyts
Liquid crystal flat optical components for efficient first order diffraction
The Hong Kong University of Science and Technology, China
Abstract
Diffractive flat optical components can achieve complex optical functionalities while using only a minimal volume. Metasurfaces based on high index materials can be used to achieve efficient diffractive devices, but the high resolution and the complexity of fabrication is often a hindrance. Liquid crystal is an anisotropic transparent material that is already widely used in large area displays, smart windows, switchable optical components and augmented reality. Diffractive components can be realized by periodic patterning of the liquid crystal alignment at the surfaces. Photoalignment can be realized with azo-dye molecules, because they align perpendicular to the polarization direction of linearly polarized blue or UV light. Complex high-resolution illumination patterns are realized by interferometry or by projection with a spatial light modulator. With this approach liquid crystal devices can be designed as diffraction gratings or holographic optical elements. Different applications will be discussed.
Biography
Kristiaan Neyts received his M.S. and Ph.D. degrees at Ghent University in Belgium in 1987 and 1992. After pos-docs at UGent and UC Berkeley, he became assistant professor in 2000 and full senior professor in 2012 at Ghent University in the Electronics and Information Systems Department, Faculty of Engineering, Since September 2023 he is professor at the Hong Kong University of Science and Technology (HKUST) in the Department of Electronic and Computer Engineering (ECE) and Director of the State Key Laboratory of Advanced Displays and Optoelectronics Technologies (SKLADT). Kristiaan Neyts is co-author of over 300 scientific papers in international journals and promoter or co-promoter of 34 completed PhDs. His research is in the field of liquid crystals (photoalignment, gratings, diffractive optics and displays), organic LEDs (outcoupling), electrophoresis (displays, smart windows and particle trapping) and color science.
Qiong-Hua Wang
Light field 3D display based on integral imaging
Beihang University, China
Abstract
Light field 3D display is an important 3D display. This talk will give an overview of light field 3D display technology, and introduce in detail a desktop light field 3D display and a high-resolution light field 3D display based on integral imaging developed by our team. The former achieves good 3D display effect with 360° horizontal view angle, and the latter achieves good 3D display effect with high resolution. The structure, principle and performance of the light field 3D displays will be elucidated. Finally, the development trend of the light field 3D display will be discussed.
Biography
Qiong-Hua Wang is a professor of optics at Beihang University. She was a professor at Sichuan University from 2004 to 2018. She was a research scientist at the School of Optics/CREOL at the University of Central Florida from 2001 to 2004. She was a faculty at the University of Electronic Science and Technology of China (UESTC) from 1995 to 2001. She received B. S., M. S. and Ph. D. degrees from UESTC in 1992, 1995 and 2001, respectively. She published about 400 papers cited by science citation index and authored 3 books. She holds about 200 U. S. and Chinese patents. She is fellow of SID, OPTICA, SPIE, COS and CSOE. Her research interests include display and imaging technologies.