Title: Compound semiconductor nanowires
Speaker: Prof. Takashi Fukui (Hokkaido University, Japan)
Time: 15:00, Jul. 23, 2010
Venue: Academic Salon, Institute of Semiconductors, CAS
Abstract: Semiconductor nanowires have stimulated extensive interest in recent years because of their unique properties and potential applications as building blocks for nanoscale electronic and photonic devices. We report on the systematically controlled growth of III-V nanowire arrays by catalyst-free selective area metalorganic vapor phase epitaxy (SA-MOVPE) on partially masked (111) oriented substrates. First, we fabricated single GaAs/GaAsP coaxial core-shell nanowire lasers. PL spectra from a single nanowire indicate that the obtained heterostructures can produce 816nm near-infrared lasing under pulsed light excitation at 4.2K. Next, we fabricated vertical InAs nanowire channel FET transistors on Si substrates with high-k/metal gate-allaround structures. The best device exhibited maximum drain current, maximum transconductance on–off ratio of 83uA/um, 83uS/um, and 104, respectively. A periodically aligned dense core–shell InP nanowire array was fabricated and used in photovoltaic device applications. As-grown nanowire solar cell covering 2.0×2.6mm2 area exhibited open-circuit voltage, short-circuit current and fill factor levels of 0.43 V, 13.72mA/cm2 and 0.57, respectively, which indicated a solar power conversion efficiency of 3.37% under AM1.5G illumination. Finally, we demonstrate vertical InAs and GaAs nanowire growth on Si (111) substrates by modifying initial Si (111) surface. Cross-sectional transmission electron microscope showed that misfit dislocation with local strains was accommodated in InAs/Si interface, while no misfit dislocation was observed in GaAs/Si interface.
About speaker：
Takashi Fukui is a professor in the Graduate school of Information Science and technology at Hokkaido University, Japan and from 2005 he serves as a director of Research Center for Integrated Quantum Electronics. He received his BS and MS degrees in applied physics and Ph.D. degree in engineering from Hokkaido University, Sapporo, Japan in 1973, 1975 and 1983 respectively. His area of research encompasses the formation of quantum nanostructures and their application. He was instrumental in developing the MOVPE growth facility. By his extensive research he was successful in forming the InGaAs quantum wire lasers, GaAs single electron transistors and their logic circuits. His research interest also includes studies of optical and transport properties of GaAs and InAs quantum dots and currently semiconductor nanowires. He has more than 200 publications in JCR scientific journals to his credit and his papers have been cited more than 3,500 times in other journal articles. He was a chairman of International Conference of Metalorganic Vapor Phase Epitaxy (ICMOVPE-X) held in Sapporo in 2000. He is an active member of the American Physical Society, the Japan Society of Applied Physics, the Japanese Association for Crystal Growth and of several other scientific and professional associations.