日期：2022/05/31 - 2022/05/31
主讲人：Dr. Renjie Wang, Research Associate with the Electrical and Computer Engineering, University of Virginia
“More than Moore” technologies require the use of micro- and nano-scale materials and devices for integration into a limited space, heterogeneous integration of existing device functions, miniaturization of circuits and systems, and others. In this talk, I will present the development of various nanoscale and microscale optoelectronic and electronic device components by engineering low dimensional materials and device structures. These extreme manufacturing are based on different material systems spanning the ultraviolet (UV) to the infrared (IR) regimes. III-nitride nanocrystals and microcrystal have emerged as the building blocks of future UV-visible optoelectronic and electronic devices. Driven by the needs for reduced power consumption and enhanced efficiency and functionality, future ultrahigh resolution display and smart lighting technologies require the development of small size, efficient, multi-color light sources monolithically and precisely integrated on a single chip. The monolithic integration of blue, green, red, and yellow/orange InGaN nanocrystal LEDs on Si substrate or GaN/sapphire substrate have been achieved by using molecular beam epitaxy (MBE). Such controllable and tunable full-color light generations were realized by using selective area growth and fabrication. Three approaches to monolithic integration have been investigated to realize microscale pixels. To suppress nonradiative surface recombination of InGaN nanocrystal LEDs, spontaneously formed nanoscale core-shell structures have been realized to enhance their carrier lifetime and output power. In addition, high precision selective area epitaxy technique of GaN-based nanocrystals has been realized using n-Si as a conductive substrate. Device applications including LEDs, solar cells, and photoelectrochemical hydrogen production have been demonstrated using (Al)InGaN nanorod arrays precisely grown on Si. For the infrared regime, n-barrier-n III-V digital alloy photodetectors have been developed by engineering III-V superlattices at monolayer scale in an MBE chamber. In addition, I will also discuss roll-to-roll (R2R) manufacturing of flexible Ge films and a CMOScompatible and wafer-scale process to develop Er3+ -Yb3+ doped oxide on-chip optical amplifiers.
Dr. Renjie Wang received the B.S. degree in Energy Engineering from Zhejiang University, Hangzhou, China, in 2010, the M.S. degree in Mechanical Engineering from University of Houston, Houston, United States, in 2012, and the Ph.D. degree in Electrical Engineering from McGill University, Montreal, Canada, in 2018. In 2019-2020, he was a postdoctoral researcher with the Engineering Physics at McMaster University, Hamilton, Canada. He is currently a Research Associate with the Electrical and Computer Engineering, University of Virginia, Charlottesville, United States. His research interests include design, epitaxy, micro/nano fabrication, and characterization of novel semiconductor materials and devices, and their device integrations for photonic and electronic applications.