Recent scientific paper discussing the interface properties and doping of graphene co-authored by ECE alumni Dr. Yasin Khatami (PhD ’13) and Dr. Hong Li (PhD ’12) has been featured on the cover page of the January 2014 issue of the IEEE Transactions on Nanotechnology (TNANO).
This TNANO article titled, On the Electrostatics of Bernal-Stacked Few-Layer Graphene on Surface Passivated Semiconductors, by Y. Khatami, H. Li, W. Liu and K. Banerjee, investigated the electrostatics and charge screening of Bernal-stacked few-layer graphene on surface passivated semiconductors—an important issue for optimizing graphene in transparent conductor applications.
TNANO is an interdisciplinary journal that is published bi-monthly and covers all aspects of nanotechnology including nanoscale devices, systems, materials and applications, and their underlying science.
Both Dr. Khatami and Dr. Li’s doctoral work was supervised by ECE Professor Kaustav Banerjee.
Electrical & Computer Engineering, Computer Engineering and the College of Engineering each ranked 11th among public universities
Kaustav Banerjee, professor of electrical and computer engineering at UC Santa Barbara, and Director of the Nanoelectronics Research Lab, is spending the winter quarter of 2014 in Japan on an Invitation Fellowship of the Japan Society for the Promotion of Science.
Banerjee and his research group are internationally recognized for their contributions in nanoelectronics. “Our current focus is on the use of low-dimensional materials such as graphene and other two-dimensional crystals to design high-performance, energy-efficient ‘green’ electronics,” explained Banerjee. “This prestigious fellowship with JSPS recognizes and supports our research in nanoelectronics, particularly in the area of 2D crystals.”
These atomically-thin materials could potentially revolutionize a number of scientific fields and also open new pathways in nanoelectronics, photonics and bioelectronics. Banerjee’s pioneering efforts in low power integrated circuits using key advances in nanomaterials, nano- devices and circuits, and design methods have played a role in steering the semiconductor industry’s research and development efforts.
The David Sarnoff Award, sponsored by SRI International Sarnoff, recognizes Coldren for his contributions to semiconductor lasers and photonic integrated circuits.
Coldren, an IEEE Life Fellow and the Fred Kavli Professor of Optoelectronics and Sensors at UCSB, is a leading authority on semiconductor lasers and photonic integrated circuits. His work has shaped the optical communications field and provided key devices for high-capacity lightwave transmission systems.
His development and commercialization of key laser and photonics technologies have been integral to enhancing the capacity and spectral efficiency of optical transmission systems. Perhaps his most outstanding innovation was the conception, development and commercialization of the sampled-grating distributed-Bragg-reflector laser. Containing a modulator and amplifier fabricated on the same semiconductor chip as a widely-tunable laser, this device is the workhorse transmitter for high-capacity lightwave transmission systems in many of today’s telecom core networks.
Coldren has also made seminal contributions to the design of vertical-cavity surface-emitting lasers, which are integral to routing e-mail and Internet traffic. He is a technical authority on photonic integrated circuits, whose functionality, low cost and small footprint will play an important role in ultra-high-speed optical systems.
The award will be presented in March 2014 at the IEEE Optical Fiber Communications Conference and Exposition.
UC Santa Barbara is one of several institutions participating in investigation and innovation at the Next Generation Power Electronics Institute, a newly established research and manufacturing hub aimed at strengthening the U.S. economy.
President Obama announced the establishment of this new public-private partnership in remarks made at North Carolina State University (NCSU), the lead university and headquarters of this new consortium.
“This has to be a year of action,” said the president, commenting on his administration’s push to help the country recover from the lean years of the nation’s worst economy since the Great Depression. “Manufacturing is a bright spot in this economy.”
Tying innovation and research to business, the Next Generation Power Electronics Institute is a federally funded institute composed of 18 companies and seven universities and labs working together to further develop and commercialize wide bandgap semiconductors — semiconductor materials that are emerging as the future of power electronics for their energy efficiency, durability and reliability at higher voltages and frequencies. Further development of these semiconductors has the potential for smaller, faster, cheaper and more efficient devices, from smartphones to electric cars, to more responsive and flexible power grids.
Mishra, a professor of electrical and computer engineering at UCSB, is recognized worldwide for his contributions to the development of gallium nitride (GaN) electronics. As one of several directors in the new consortium, his efforts will focus on leading the thrust for research and development of highly efficient GaN-based wide bandgap semiconductors. “This is just a first step,” said Mishra. “I think this institute is going to cause more excitement, more synergies, and people will become more fluent with what we can do.”
“We’re thrilled to be part of this,” said Rod Alferness, dean of UCSB’s College of Engineering. “It reflects the high level of esteem and regard that the work here in gallium nitride-based electronics is held here in the community and at the corporate level.”
UCSB College of Engineering professors Steven DenBaars (ECE & Materials) and Samir Mitragotri (ChemE) recognized by the NAI for their “highly prolific spirit of innovation.” Denbaars and Mitragotri are the first among UCSB’s faculty to be elected to the rank of Fellow in the NAI.
“It is a great honor to be recognized for my inventions by NAI, and to have my research supported by UCSB for over 20 years,” said DenBaars, professor of materials and of electrical and computer engineering at UCSB. DenBaars is the co-director of the Solid State Lighting and Energy Center and holder of the Mitsubishi Chemical Chair in Solid State Lighting and Displays at UCSB.
DenBaars’ research focuses on electronic materials growth and semiconductor devices, particularly in the realm of compound semiconductors such as indium phosphide and gallium nitride (GaN). He holds more than 165 patents, with several more pending on GaN growth and processing. Recently, he was part of a team that determined the optimal structure for phosphors (a key component in LED lighting), a breakthrough that can lead to brighter and more efficient LED lights.
Induction into the NAI is the latest of several honors Denbaars has received over the course of his career. DenBaars is a Fellow of the prestigious National Academy of Engineering (NAE) and the Institute of Electrical and Electronics Engineers (IEEE), and was the recipient of the Aron Kressel award from the IEEE Photonics Society. DenBaars earned his Ph.D. in electrical engineering from the University of Southern California.
DenBaars and Mitragotri will be inducted into the Academy at a ceremony in March 2014 in Alexandria, Va., at the USPTO headquarters.
The semiconductor industry has been confronting an acute problem in the interconnect area. As IC feature sizes are scaled below 14 nm, copper wires exhibit significant “size effects” resulting in a sharp rise in their resistivity. This has adverse impact on IC performance and reliability in the form of higher communication costs due to increased interconnect delays and chip-level power dissipation, as well as due to reduced current carrying capacity of the copper wires. Carbon nanotubes (CNTs) have very high current carrying capability (at least two orders of magnitude higher than that of copper), long mean free path (on the order of μm), and high thermal conductivities (several times higher than that of copper), indicating that CNTs could be potentially employed as alternative materials for next-generation nanoscale interconnects. Such interconnects can enhance the electrical performance as well as eliminate reliability concerns that plague nanoscale copper interconnects.
However, fabrication and characterization of long and horizontal CNT-bundles necessary for interconnect applications have remained an enigma. In a game-changing development, ECE researchers led by Prof. Kaustav Banerjee in collaboration with NASA Ames and TU-Munich have demonstrated a novel process that, for the first time, enables fabrication of high-density, long (over 100 microns) and thick (up to microns) horizontally aligned CNT interconnects. This demonstration has thus overcome one of the biggest challenges facing the CNT interconnect technology and is a vital step for implementation of CNT based interconnects and passive devices in next-generation VLSI. The developed process not only yields horizontal CNT interconnects with the lowest reported resistivity, but also enables the first ever fabrication of a CNT based on-chip spiral inductor. These results have been recently published in the IEEE Transactions on Electron Devices by ECE alum Dr. Hong Li et al.
Zuli levergages smartphone usage to help control homes with lights / appliances adjusting to the user’s preferences which also aids in energy efficiency.
The Zuli smartplug communicates with a smartphone using Bluetooth Low Energy, giving unmatched control, monitoring and automation at an affordable price.
Features include on/off control, dimming, location based automation, energy monitoring, away detection, scheduling and more.
UC Santa Barbara researchers demonstrate seamless designing of an atomically-thin circuit with transistors and interconnects etched on a monolayer of graphene
Researchers in electrical and computer engineering at UC Santa Barbara have introduced and modeled an integrated circuit design scheme in which transistors and interconnects are monolithically patterned seamlessly on a sheet of graphene, a 2-dimensional plane of carbon atoms. The demonstration offers possibilities for ultra energy-efficient, flexible, and transparent electronics.
Bulk materials commonly used to make CMOS transitors and interconnects pose fundamental challenges in continuous shrinking of their feature-sizes and suffer from increasing “contact resistance” between them, both of which lead to degrading performance and rising energy consumption. Graphene-based transistors and interconnects are a promising nanoscale technology that could potentially address issues of traditional silicon-based transistors and metal interconnects.
“In addition to its atomically thin and pristine surfaces, graphene has a tunable band gap, which can be adjusted by lithographic sketching of patterns – narrow graphene ribbons can be made semiconducting while wider ribbons are metallic. Hence, contiguous graphene ribbons can be envisioned from the same starting material to design both active and passive devices in a seamless fashion and lower interface/contact resistances,” explained Kaustav Banerjee, professor of electrical and computer engineering and director of the Nanoelectronics Research Lab at UCSB. Banerjee’s research team also includes UCSB researchers Jiahao Kang, Deblina Sarkar and Yasin Khatami. Their work was recently published in the journal Applied Physics Letters.
By determining simple guidelines, researchers at UC Santa Barbara’s Solid State Lighting & Energy Center (SSLEC) have made it possible to optimize phosphors –– a key component in white LED lighting –– allowing for brighter, more efficient lights.
“These guidelines should permit the discovery of new and improved phosphors in a rational rather than trial-and-error manner,” said Ram Seshadri, a professor in the university’s Department of Materials as well as in its Department of Chemistry and Biochemistry, of the breakthrough contribution to solid-state lighting research. The results of this research, performed jointly with materials and electrical and computer engineering professor Steven DenBaars and postdoctoral associate researcher Jakoah Brgoch, appear in The Journal of Physical Chemistry.
LED (light-emitting diode) lighting has been a major topic of research due to the many benefits it offers over traditional incandescent or fluorescent lighting. LEDs use less energy, emit less heat, last longer and are less hazardous to the environment than traditional lighting. Already utilized in devices such as street lighting and televisions, LED technology is becoming more popular as it becomes more versatile and brighter.