Hikaru Sasaki (M2), Department of Electrical Engineering and Information Systems, received the 60th Japan Society of Applied Physics Young Scientist Presentation Award

On 8th September 2026, Hikaru Sasaki (M2), Maeda Lab, Department of Electrical Engineering and Information Systems, received the 60th Japan Society of Applied Physics (JSAP) Young Scientist Presentation Award.

The 60th Japan Society of Applied Physics Young Scientist Presentation Award 

The Japan Society of Applied Physics (JSAP) Young Scientist Presentation Award is given at JSAP's Spring and Autumn Meetings to young members who have presented outstanding general oral presentations contributing to the advancement of applied physics, in recognition of their achievement. Recipients are selected within a limit of 1.5% of the total number of general oral presentations.

About awarded research
In recent years, basic research aimed at expanding material selectivity and functionality—by modulating lattice constant and bandgap, enhancing spontaneous polarization and piezoelectricity, and inducing ferroelectricity—through the addition of heteroelements such as Sc and B to conventional nitride semiconductors (GaN, AlN, InN) has become increasingly active. We have previously succeeded in epitaxially growing wurtzite-structured NbAlN alloys with large polarization on GaN by adding Nb [1]. In this study, we investigated the surface oxidation state of this novel nitride material NbAlN in detail and systematically using synchrotron radiation spectroscopy, and clarified the surface oxidation mechanism of NbAlN through photon-energy dependence and peak spectral analysis. In particular, we found that surface oxidation is somewhat suppressed as the Nb composition increases, and by comparing and discussing this with the case of ScAlN (where surface oxidation increases markedly with increasing Sc composition), we showed that the behavior can be consistently explained in terms of Pauling electronegativity. The findings obtained in this study will be highly useful for the research and development of optoelectronic devices using novel nitride materials such as NbAlN.

Authors：Hikaru Sasaki, Takahito Takeda, Akihira Munakata, Masaki Kobayashi, Atsushi Fujimori, Tomoya Okuda, Sota Kurogi, Atsushi Kobayashi, Takuya Maeda
Presentation title：Evaluation of Surface Oxidation States of Sputter-Epitaxially Grown NbAlN Thin Films on GaN by X-ray Spectroscopy
Conference: 73rd JSAP Spring Meeting, 15p-SL_101-9, Institute of Science Tokyo, Ookayama Campus, March 2026.

[1] Press release: "NbAlN: A New Polar Wurtzite Nitride Semiconductor Containing Niobium —Enhancing the interface electron density in GaN-based heterostructures, expanding polarization material and device design—"
https://www.t.u-tokyo.ac.jp/en/press/pr2026-09-07-001 
Paper information:
Journal: Advanced Materials
Title: Polar Wurtzite NbAlN: A Transition-Metal Nitride Alloy for Polarization-Engineered GaN Heterostructures
Authors: Atsushi Kobayashi, Souta Kurogi, Tomoya Okuda, Riku Kikuchi, Yusuke Wakamoto, Kouei Kubota, Hikaru Sasaki, Kazuhisa Ikeda, Kanako Shojiki, Takahiro Kawamura, Toru Akiyama, Takehito Seki, Takuya Maeda
DOI: 10.1002/adma.74756b

Your impression & future plan 

It is a great honor to receive this prestigious award. I would like to thank Professor Maeda for his continual guidance, my collaborators for their guidance and cooperation, and the members of our laboratory for their support. I will continue to devote myself to my research going forward.