Takamasa Kawanago

Ultra-low Voltage WSe2 CMOS Integrated Circuits

Researcher

Takamasa Kawanago

Outline

This project will establish the fundamental technology for ultra-low voltage operating CMOS integrated circuits using tungsten diselenide (WSe2). For ultra-low voltage operation of WSe2 CMOS devices and circuits, this project will address the realization of double-gate operation in which the WSe2 channel is sandwiched between upper and lower gate stacks, construction of n/p FETs using non-doped WSe2 channels and development of a unique self-aligned process. Furthermore, this project also will apply the fabricated WSe2 CMOS devices for chip-level ultra-low voltage operating WSe2 CMOS integrated circuits.

Yui Sasaki

Development of nanodevices based on molecular self-assemblies

Researcher

Yui Sasaki

Outline

Molecular self-assemblies can be driving forces to spontaneously fabricate functional nanostructures with high molecular orientation. This research aims to establish a methodology for the development of nanodevices based on molecular interactions.

Hirokazu Tahara

Development of efficient optoelectronic devices with quantum cooperativity in nanomaterial superstructures

Researcher

Hirokazu Tahara

Outline

Collective nanomaterials can generate strong optical responses via their cooperative processes. In this research, I will develop optoelectronic devices with quantum cooperativity in collective nanomaterials to demonstrate efficient infrared-visible light-energy conversions. Nanomaterial superstructures are used to generate strong quantum cooperativity. I will clarify the mechanism of light-energy conversion in nanomaterial superstructures and establish methods for using quantum cooperativity in energy-conversion and information-conversion devices.

Takashi Tsuchiya

Creation of ultrafast iontronics

Researcher

Takashi Tsuchiya

Outline

While iontronics is a powerful method to explore untouched electronic functionalities of materials due to its capability of extremely high density electronic carrier accumulation by electric double layer effect, the slow operation speed has been limiting the range of application. In the present study, electric double layer response of iontronic devices is investigated in the view points of physical and chemical properties of components (electrolytes, channel semiconductors), interfaces, and device structures, in order to build a guiding principle for creation of ultrafast iontronic devices with various nanomaterials operating far faster than conventional ones.

Yusuke Nakanishi

Fabrication and characterization of one-dimensional heterojunctions inside nanospaces

Researcher

Yusuke Nakanishi

Outline

Atomically thin one-dimensional (1D) materials, known as ‘atomic wires’, which are typically fabricated inside nanospaces such as nanotubes, have emerged as promising components for nanoelectronic devices. However, their studies and applications have been severely hindered due to the difficulties in connecting electrodes. This study focuses on the fabrication and comprehension of the heterojunctions confined in 1D nanospaces to facilitate the integration of electrodes with atomic wires. Ultimately, the objective of this project is to pave the way for practical electronic applications of atomic wires.

Hiroyasu Nakayama

Highly reliable voltage-driven spintronic devices by interface engineering

Researcher

Hiroyasu Nakayama

Outline

In the super smart society of the future, there are concerns about a huge increase in power consumption as the number of IoT devices increases rapidly. Therefore, a computer system that operates with lower power consumption is desired to be achieved. From the viewpoints of high-speed operation, non-volatility, and low write power consumption, voltage control of spins is a promising technology for next-generation memory devices. However, there is a fatal problem with the high write error rate in conventional dynamic method. This project aims to create a novel method for voltage control of spins with much higher reliability by exploiting long-range interactions those act on the ultrathin magnetic films and their interfaces.

Naoki Higashitarumizu

Large-scale mid-infrared optoelectronics based on narrow-gap 2D materials

Researcher

Naoki Higashitarumizu

Outline

The growing demand for mid-infrared light has gained prominence across various applications, including gas sensing, night vision, disaster prevention and security, building maintenance, and automotive technologies. In this project, my focus lies in harnessing the exceptional optical characteristics exhibited by narrow-gap 2D semiconductors. The overarching goal is to pioneer the development of novel materials and innovative processes that will yield superior performance in mid-infrared optoelectronic devices. This research endeavors span not only the single device on a microscale but also encompass the large area integrations on a chip to wafer scale.

Toshinori Matsushima

Enhanced carrier transport in two-dimensional perovskites

Researcher

Toshinori Matsushima

Outline

Field-effect transistors with a two-dimensional perovskite semiconductor layer containing carrier-transporting organic amines are fabricated. This innovative approach enables ambipolar operation by dividing carrier transport between the organic amine layer and the metal halide layer. Through the optimization of the perovskite film fabrication processes, grain boundary density and defect density are reduced, thus accelerating carrier transport.

Masakazu Matsubara

Creation of opto-spintronic functionalities by controlling the symmetry of nanospace

Researcher

Masakazu Matsubara

Outline

The various functionalities exhibited by materials are closely linked to the symmetry of their inherent electronic degrees of freedom. In this research, I will develop various thin-film artificial materials with manipulated nanospace symmetry ―two-dimensional metamaterials－ and establish fundamental technologies for creating novel opto-spintronic functionalities that are not bound by the intrinsic properties of materials, such as optical spin current generation/control and spin photoelectric conversion based on new principles.

Masataka Mogi

Emergent topological properties from thin film interface and structural heterogeneity

Researcher

Masataka Mogi

Outline

Spatially inhomogeneous structures, known as moiré superlattices, emerge from twisted two-dimensional materials, leading to unconventional electronic and optical responses. In this research program, I extend the concept of spatial inhomogeneity in quantum matter using advanced molecular beam epitaxy techniques, aiming to explore new electronic functionalities that utilize topological states of matter. Specifically, I develop novel methods to create superstructures that are distinct from moiré superlattices, achieved through the design of interfacial strain or compositional control. Furthermore, I aim to realize a novel light-induced topological phase switch via highly nonequilibrium states using advanced ultrafast laser techniques.