Professor Hiroshi Amano received Doctor of Engineering from Nagoya University. Currently he is a Director, Center for Integrated Research of Future Electronics, and a Professor, Institute of Materials and Systems for Sustainability, Nagoya University.
He shared the 2014 Nobel Prize in Physics with Prof. Isamu Akasaki and Prof. Shuji Nakamura "for the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources". He is currently developing technologies for the fabrication of high-efficiency power semiconductor development and new energy-saving devices at Nagoya University.

Metalorganic vapor phase epitaxy (MOVPE) plays a central role in the growth of compound semiconductor wafers—arsenides, phosphides, nitrides, and their heterostructures and quantum structures—used in high‑frequency electronics, photonics, lighting, and display devices. These devices support modern society by enabling wireless and optical communication networks, linking Si LSI chips, providing high‑quality full‑color displays, and realizing sustainable solid‑state lighting. In this sense, MOVPE has become a foundational technology that underpins our social infrastructure. In contrast to these well‑established application fields, power electronics has historically been dominated by Si‑ and SiC‑based devices. Recently, however, MOVPE-grown GaN high-electron-mobility transistors (HEMTs) on Si substrates have begun to transform this landscape. GaN-on-Si HEMTs offer MHz‑order and higher switching speeds, enabling the marked miniaturization of power converters. This technology has led to compact AC adapters for PCs and smartphones, and is opening new markets for high‑frequency power conversion. Nevertheless, the controllable power of lateral GaN-on-Si HEMTs remains limited to the 60-600 W range because the current‑carrying area is restricted to the interface between the barrier and channel layers. Achieving higher breakdown voltages requires increasing the chip size, which constrains scalability. To extend the impact of MOVPE-grown nitride semiconductors to high‑power electrical equipment and even power‑grid‑level systems, the development of vertical GaN power devices with thick, high‑purity drift layers and fine‑pitch device structures is essential. Natural GaN substrates and Qromis Substrate Technology offer promising platforms for realizing such vertical GaN devices. However, growing thick, high‑purity drift layers by MOVPE remains a major challenge due to carbon incorporation from metal–organic precursors. Overcoming this limitation is critical for realizing next‑generation, high‑power GaN‑on‑GaN devices. In this presentation, I will discuss recent progress and remaining challenges in MOVPE growth for vertical GaN power electronics, and explore pathways toward their future implementation in societal infrastructure.
I would like to thank all my colleagues, especially Professors Yoshio Honda, Jun Suda, Manabu Arai, Atsushi Tanaka, Manato Deki, and Maki Kushimoto for fruitful discussions. This work was partly supported by the MEXT program for the Creation of Innovative Core Technology for Power Electronics, (grant no. JPJ009777), the JST ASPIRE program (grant no. JPMJAP2311), and the Japan Society for Promotion of Science KAKENHI (grant nos. 22J15656 and JPH00213).

Nicolas Grandjean received his PhD in physics from the University of Nice–Sophia Antipolis in 1994 and subsequently joined the French National Centre for Scientific Research (CNRS) as a staff scientist. In 2004, he was appointed tenure-track assistant professor at the École polytechnique fédérale de Lausanne (EPFL), where he founded the Laboratory for Advanced Semiconductors for Photonics and Electronics. He was promoted to full professor in 2009. From 2012 to 2016, he served as Director of the Institute of Condensed Matter Physics at EPFL and was a visiting professor at the University of California, Santa Barbara, in 2016. Between 2018 and 2022, he headed the EPFL School of Physics. In 2025, he was appointed Associate Vice-President for Education. Professor Grandjean has received numerous distinctions, including the Sandoz Family Foundation Grant for Academic Promotion, the Nakamura Lecturer Award (2010), the Quantum Devices Award at the 2017 Compound Semiconductor Week, and the EPFL Best Teacher Award in 2022. He has authored more than 600 peer-reviewed publications and has delivered plenary talks at major international conferences. His research focuses on the physics and technology of III-V nitride wide-bandgap semiconductors.

Blue light-emitting diodes (LEDs) based on III-V nitride semiconductors have enabled the creation of semiconductor light sources with a luminous efficiency ten times greater than that of incandescent light bulbs [1]. Nowadays, these LEDs are ubiquitous in lighting applications. They have sparked a technological revolution that has significantly reduced global electricity consumption.
A remarkable feature of blue LEDs is their exceptionally high internal quantum efficiency, close to 100% at room temperature, despite an enormous dislocation density, on the order of 108 cm-2, inherited from the epitaxial growth of GaN on foreign substrates such as sapphire [2]. To understand this apparent paradox, we need to look at the properties of InGaN/GaN quantum wells (QWs), which form the core of these devices. It was first explained that carriers are localized in random alloy potential fluctuation minima and thereby cannot diffuse toward dislocations [3]. Then it was proposed that the formation of V-shaped pits around the dislocations creates an energy barrier for carriers that hinders their recombination onto the dislocations [4]. In addition to extended defects, impurities and/or native point defects could potentially be non-radiative recombination centers (NRCs) and impair the efficiency of III-nitride LEDs [5,6].
In this presentation, we will begin by discussing the actual epitaxial structure of state-of-the-art blue LEDs. It is interesting to note that they all feature an InGaN layer (or an InGaN/GaN superlattice) beneath the active QW region. We will show that this InGaN underlayer is a prerequisite for obtaining InGaN/GaN QWs with high quantum efficiency. Its role is to trap surface defects generated during the high-temperature growth of GaN by metal-organic vapor phase epitaxy [7,8]. We will demonstrate that these surface defects depend on the growth temperature and react with indium atoms to create NRCs when incorporated into InGaN/GaN QWs. The nature of these defects will be revealed by growth experiments. We will then propose a growth mechanism that explains the surface segregation of these surface defects and their incorporation as an NRC center in the InGaN layers. Finally, we will show that high-efficiency blue LEDs require careful growth optimization: i) screening of threading dislocations by forming topological defects (V-shaped pits) and ii) trapping of surface defects generated during high-temperature growth of the GaN buffer. The prospects for extreme wavelength III-nitride-based LEDs, i.e., the UV-C and red wavelength ranges, will also be discussed.

Prof. Dr. Michael Heuken was born in Germany on November 17, 1961. He received the Graduate Engineer degree and the Doctor of Engineering degree in Electrical Engineering from Duisburg University in 1985 and 1989, respectively. He joined the Institute of Semiconductor Electronics at RWTH Aachen University and has been working in the field of metalorganic vapor phase epitaxy for electronic and optoelectronic devices. He has been lecturer for semiconductor technology and devices as well as circuits for communication systems at RWTH. In 1997 he joined AIXTRON in Aachen/Germany where he is now Vice President Advanced Technologies. In 1999 he was honored as Professor at RWTH Aachen University. His experience is in the field of semiconductor growth by MOVPE. Prof. Heuken is co-author of more than 750 publications in international journals and several invited papers at international conferences. He was President of German Crystal Growth Association, he served as elected Executive Committee Member of the IOCG, he is member of VDE/ITG. Currently he serves as Board Member of NMWP e.V. and Advanced UV for Life e.V. He acts as referee for international journals and supports several organizations as an expert. Prof Heuken has been granted several patents in the field of semiconductor technology. The scientific contributions to compound semiconductor technology especially MOCVD were recognized by the Laudise-Price of the IOCG in 2025.

Compound semiconductor devices - such as those made from materials like Gallium Arsenide (GaAs), Indium Phosphide (InP), and Gallium Nitride (GaN) play a crucial role in advancing technologies that align with several United Nations Sustainable Development Goals. To enable LED for solid state lighting applications, advanced multi junction solar cells or power saving transistor technologies we developed the Metalorganic Chemical Vapor Phase Deposition (MOCVD or MOVPE) technology for III-As/P/N based structures in MOCVD-systems ranging from small scale to large production scale reactors. This technology enables the industrial introduction of high-volume device families which require dedicated layer sequences with exactly specified properties uniformly distributed across wafer diameter up to 300 mm.
The requirements for the process equipment are manifold, demanding utmost control of purity, composition and interfaces, dopant and layer thickness uniformity and low defect density of the epitaxial quantum structures. Besides layer quality, the ability to manufacture the device layer stacks reproducibly and economically is crucial to support the growing demand.
The focus of epitaxy production technology developments based on scientific understanding has been put on material properties close to the physical limit, improved process control, productivity enhancement concepts like wafer level automation, in-situ metrology to acquire process data for smart system control and predictive maintenance concepts. A comprehensive summary and recent progress in cost-down strategies and improved technical specifications will be reported here. The application of the underlying physical, technical and chemical fundamentals supports the engineering approaches to achieve economic, technical, and scientific objectives.
The upcoming new 2D materials classes such as transition metal dichalcogenides (TMDC) or graphene will find their application in electronic and optoelectronic devices such as memristive devices for energy efficient neuromorphic computing and quantum sensors or in sub 2 nm CMOS like AI chips.
The application of the detailed understanding of the fundamentals of MOCVD, consequently designing and optimizing epitaxial equipment and processes and managing their transfer to industry will be explained by using several examples such es these novel 2D materials.

Joan Redwing is a Distinguished Professor of Materials Science and Engineering and Electrical Engineering at Penn State University. She currently serves as Director of the 2D Crystal Consortium (2DCC), an NSF Materials Innovation Platform national user facility in the U.S. that is focused on advancing the synthesis and characterization of 2D materials for next generation devices. Her research focuses on crystal growth and epitaxy of electronic materials, with an emphasis on thin film and nanomaterial synthesis by metalorganic chemical vapor deposition. She is a fellow of the Materials Research Society, the American Physical Society, and the American Association for the Advancement of Science. She is an author on over 350 publications in refereed journals and holds 8 U.S. patents.

Two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs), exemplified by materials like MoS2 and WSe2, have garnered increasing interest for next generation electronics such as gate-all-around nanosheet transistors, neuromorphic devices and sensors/imagers heterogeneously integrated with silicon CMOS technology. The interest in semiconducting TMDs arises from their atomically thin nature and passivated van der Waals surfaces, however, realization of high-performance devices requires advances in TMD synthesis to provide wafer-scale films that can be readily integrated into devices via either direct growth or layer transfer methods.

Our work has focused on the development of metalorganic chemical vapor deposition (MOCVD) as a manufacturing-compatible approach for wafer-scale semiconducting TMDs. The TMDs are grown epitaxially on 2” diameter c-plane sapphire by MOCVD at elevated temperatures (>800 °C) to obtain high crystal quality. Nucleation of TMDs on sapphire is intimately tied to the surface structure and the growth chemistry which can be controlled to achieve unidirectional TMD domains with a significant reduction in mirror twin domains in coalesced films. In situ spectroscopic ellipsometry is demonstrated to be an effective real time monitor of TMD growth even at the sub-monolayer level which can be exploited to track surface coverage as a function of time under varying growth conditions. The ability to precisely control and modulate precursor flux during growth is used to synthesize in-plane heterostructures that enable localized exciton confinement and emission. Applications for wafer-scale TMD monolayers in nanoelectronics, sensing and photonics will be discussed.