Title: Integrating III-V quantum dot lasers on silicon platform for silicon photonics
Speaker: Huiyun Liu（Professor of Semiconductor Photonics, Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE, England; http://www.ee.ucl.ac.uk/staff/academic/hliu）
Time: May. 3, 2016 10:00AM
Venue: No. 101 Meeting Room of the library, IOS, CAS
Abstract: Silicon is one of the most important semiconductor materials. Although it has been the mainstays for modern electronics, it is not widely used for light emitting sources because bulk silicon is an inefficient emitter, a result of indirect bandgap. Direct epitaxial growth of III-V nanostructures on silicon substrates is one of the most promising candidates for realizing photonic devices on a silicon platform.
In this presentation, the growth of III-V quantum dots - semiconductor nanosized crystal - on Si substrates and their applications in communications will be discussed. I will describe new growth techniques developed at University College London for the formation of III-V buffer layers grown directly on Ge, Si and Ge/Si substrates by Molecular Beam Epitaxy (MBE). This work has lead to the first practical silicon-based laser diode with pulsed (cw) lasing up to 120 oC (75 oC), with an ultra low cw threshold current density 62.5 A/cm2, a high output power exceeding 105 mW at RT, and a long extrapolated lifetime of over 100,158 hours [Nature Photonics: DOI: 10.1038/NPHOTON.2016.21]. These results are a major step towards silicon-based photonics and photonic-electronic integration, and provide a route towards cost-effective monolithic integration of III-V devices on Si platform.
Biography：PhD Thesis is on III-V quantum-dot materials and laser diodes form Institute of Semiconductor, Chinese Academy of Sciences at November 2001. After receiving his PhD, he joined the EPSRC National Centre for III-V Technologies at Sheffield University. In 2007, he was awarded Royal Society University Research Fellow, and started his academic career by taking Senior Lecturer (as Associate Professor in US) position in the Department of Electronic and Electrical Engineering at University College London with commissioning the first new Molecular Beam Epitaxy reactor in central London. In 2012, he was promoted as Chair (As full Professor in US) of Semiconductor Photonics at University College London. His current research interest concentrates on the nanometre-scale engineering of low-dimensional semiconductor structures (such as quantum dots and nanowires) by using MBE and the development of novel optoelectronic devices including lasers, detectors, solar cells, and modulators. He co-authored more than 300 papers and hold on several patents on silicon photonics.