http://news.rice.edu/files/2015/07/0717_HOTELECTRON-bz-lg.jpgCAPTION: Bob ZhengCREDIT: Rice University David [email protected] [email protected] Share1NEWS RELEASEEDITORS — High-resolution images are linked at the end of the news release. MEDIA CONTACTS: Rice finding could lead to cheap, efficient metal-based solar cellsPlasmonics study suggests how to maximize production of ‘hot electrons’HOUSTON — (July 22, 2015) — New research from Rice University could make it easier for engineers to harness the power of light-capturing nanomaterials to boost the efficiency and reduce the costs of photovoltaic solar cells.Although the domestic solar-energy industry grew by 34 percent in 2014, fundamental technical breakthroughs are needed if the U.S. is to meet its national goal of reducing the cost of solar electricity to 6 cents per kilowatt-hour.In a study published July 13 in Nature Communications, scientists from Rice’s Laboratory for Nanophotonics (LANP) describe a new method that solar-panel designers could use to incorporate light-capturing nanomaterials into future designs. By applying an innovative theoretical analysis to observations from a first-of-its-kind experimental setup, LANP graduate student Bob Zheng and postdoctoral research associate Alejandro Manjavacas created a methodology that solar engineers can use to determine the electricity-producing potential for any arrangement of metallic nanoparticles.LANP researchers study light-capturing nanomaterials, including metallic nanoparticles that convert light into plasmons, waves of electrons that flow like a fluid across the particles’ surface. For example, recent LANP plasmonic research has led to breakthroughs in color-display technology, solar-powered steam production and color sensors that mimic the eye.“One of the interesting phenomena that occurs when you shine light on a metallic nanoparticle or nanostructure is that you can excite some subset of electrons in the metal to a much higher energy level,” said Zheng, who works with LANP Director and study co-author Naomi Halas. “Scientists call these ‘hot carriers’ or ‘hot electrons.’”Halas, Rice’s Stanley C. Moore Professor of Electrical and Computer Engineering and professor of chemistry, bioengineering, physics and astronomy, and materials science and nanoengineering, said hot electrons are particularly interesting for solar-energy applications because they can be used to create devices that produce direct current or to drive chemical reactions on otherwise inert metal surfaces.Today’s most efficient photovoltaic cells use a combination of semiconductors that are made from rare and expensive elements like gallium and indium. Halas said one way to lower manufacturing costs would be to incorporate high-efficiency light-gathering plasmonic nanostructures with low-cost semiconductors like metal oxides. In addition to being less expensive to make, the plasmonic nanostructures have optical properties that can be precisely controlled by modifying their shape.“We can tune plasmonic structures to capture light across the entire solar spectrum,” Halas said. “The efficiency of semiconductor-based solar cells can never be extended in this way because of the inherent optical properties of the semiconductors.”The plasmonic approach has been tried before but with little success.Zheng said, “Plasmonic-based photovoltaics have typically had low efficiencies, and it hasn’t been entirely clear whether those arose from fundamental physical limitations or from less-than-optimal designs.”He and Halas said Manjavacas, a theoretical physicist in the group of LANP researcher Peter Nordlander, conducted work in the new study that offers a fundamental insight into the underlying physics of hot-electron-production in plasmonic-based devices.Manjavacas said, “To make use of the photon’s energy, it must be absorbed rather than scattered back out. For this reason, much previous theoretical work had focused on understanding the total absorption of the plasmonic system.”He said a recent example of such work comes from a pioneering experiment by another Rice graduate student, Ali Sobhani, where the absorption was concentrated near a metal semiconductor interface.“From this perspective, one can determine the total number of electrons produced, but it provides no way of determining how many of those electrons are actually useful, high-energy, hot electrons,” Manjavacas said.He said Zheng’s data allowed a deeper analysis because his experimental setup selectively filtered high-energy hot electrons from their less-energetic counterparts. To accomplish this, Zheng created two types of plasmonic devices. Each consisted of a plasmonic gold nanowire atop a semiconducting layer of titanium dioxide. In the first setup, the gold sat directly on the semiconductor, and in the second, a thin layer of pure titanium was placed between the gold and the titanium dioxide. The first setup created a microelectronic structure called a Schottky barrier and allowed only hot electrons to pass from the gold to the semiconductor. The second setup allowed all electrons to pass.“The experiment clearly showed that some electrons are hotter than others, and it allowed us to correlate those with certain properties of the system,” Manjavacas said. “In particular, we found that hot electrons were not correlated with total absorption. They were driven by a different, plasmonic mechanism known as field-intensity enhancement.”LANP researchers and others have spent years developing techniques to bolster the field-intensity enhancement of photonic structures for single-molecule sensing and other applications. Zheng and Manjavacas said they are conducting further tests to modify their system to optimize the output of hot electrons.Halas said, “This is an important step toward the realization of plasmonic technologies for solar photovoltaics. This research provides a route to increasing the efficiency of plasmonic hot-carrier devices and shows that they can be useful for converting sunlight into usable electricity.”Additional co-authors include Hangqi Zhao and Michael McClain, both of Rice. The research was supported by the Welch Foundation, the Office of Naval Research and the Air Force Office of Science and Research.-30-High-resolution IMAGES are available for download at: http://news.rice.edu/files/2015/07/0717_HOTELECTRON-pic-lg.jpgCAPTION: Rice researchers selectively filtered high-energy hot electrons from their less-energetic counterparts using a Schottky barrier (left) created with a gold nanowire on a titanium dioxide semiconductor. A second setup (right), which did not filter electrons based on energy level, included a thin layer of titanium between the gold and the titanium dioxide.CREDIT: B. Zheng/Rice UniversityA copy of the Nature Communications paper is available at:http://www.nature.com/ncomms/2015/150713/ncomms8797/abs/ncomms8797.htmlFollow Rice News and Media Relations via Twitter @RiceUNewsLocated on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation’s top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,888 undergraduates and 2,610 graduate students, Rice’s undergraduate student-to-faculty ratio is just over 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is highly ranked for best quality of life by the Princeton Review and for best value among private universities by Kiplinger’s Personal Finance. To read “What they’re saying about Rice,” go here. http://news.rice.edu/files/2015/07/0717_HOTELECTRON-am-lg.jpgCAPTION: Alejandro ManjavacasCREDIT: Jeff Fitlow/Rice University AddThis
About the AuthorKelly Vo Kelly Vo is a writer who specializes in covering MBA programs, digital marketing, and personal development.View more posts by Kelly Vo Last Updated Mar 6, 2018 by Kelly VoFacebookTwitterLinkedinemail Finally, the last thing we’re launching is an educational program that will include courses, a new website, a new blog, and a new podcast (all launching soon) that will include information from entrepreneurs, venture capitalist, product managers, blockchain, and more.Other educational programs that we will be launching include:A cross-schools educational event that we hope will help bridge the cultural gap between students in different schools.Life as an Entrepreneur: a seven-week class with a variety of speakers including founders, VCs, etc.Educational events around hot technical topics.Currently, the Berkeley Entrepreneurship Association is still in its early relaunch phase. The newly updated website will be up in the next few weeks so check back on the school website and the Berkeley Haas Entrepreneurship Program regularly to catch its launch. Connect the Entire Entrepreneurial Community Create Entrepreneurial Collaboration Entrepreneurial Education Encourage Entrepreneurship Our first mission is to encourage people to start companies. When you think about the typical MBA student who takes two years off to come to school and study, their main goal is to gain more experience and skills. Many MBA students also come to business school because they want to do something different, or possibly, follow their passions. But, when it comes to business school, entrepreneurship, generally, has a less relevant place compared to companies who offer internships or full-time positions. What we’re trying to do is encourage students to start companies and give entrepreneurship a try. regions: San Francisco The main innovation that I’m most excited about and what we’re working hard to start in the fall is a program that connects students and individuals from across different schools and different backgrounds. For the first time in Berkley’s history, it will be an initiative led by students and coordinated across different schools. I believe it will be the largest program ever created at Berkeley connecting technical and business students, student clubs, VCs, mentors, funding sources, and institutions.The goal of the program is to take great ideas and start them along the process, through customer discovery to business model evaluation. The steps are as follows:First, the program will allow people to present their innovative ideas.From there, the BEA would match the idea to a team of three or four people with different interests.Then, over three to four months, that team would work together to gather every resource they need to transform the idea into a workable concept company.Currently, the program name has not been announced, but it will be released in a few weeks. For now, everything has already been put in place, and Berkeley is ready to launch their first cycle in Fall 2018. RelatedHaas Re-vamps LAUNCH CompetitionThe Haas School of Business has revamped its LAUNCH start-up competition. The program now has new eligibility requirements, and has been developed from a startup idea competition into a four-month accelerator designed to transform early-stage startups into fundable ventures. Top Berkeley-Haas leaders and faculty, including serial entrepreneur and Berkeley-Haas Lecturer…November 12, 2014In “Featured Home”UC Berkeley Students Award Faculty and Graduate Instructors Cheit Teaching AwardsSix professors and two graduate student instructors at University of California, Berkeley’s Haas School of Business will be honored at the commencement this month for their excellence in teaching. A panel of students who selected the Cheit Award recipients from student nominations chose the professors and instructors to be awarded.…May 21, 2014In “News”Venture Creation Thrives with a Berkeley Haas MBAMBAs from the Haas School of Business at UC Berkeley (Berkeley Haas) have ideal access to the hub of entrepreneurship and venture creation that continues to thrive in the Bay Area. Last year, a record number of both full-time MBA students and those in the first cohort of the executive…April 28, 2016In “Featured Region” Entrepreneurship at the Haas School of Business at UC Berkeley is getting an upgrade. Right now the university is working to rebrand and relaunch the Berkeley Entrepreneurship Association (BEA). While the newly updated BEA isn’t available yet, it’s in the works and will have many exciting announcements over the next weeks and months.We were lucky enough to get an inside look at what’s coming to the BEA in a talk with Luca Cosentino, MBA’19, the President and Co-Chair of the BEA and the man behind the re-launch. Here’s the inside scoop!MetroMBA: What is the Berkeley Entrepreneurship Association (BEA)?Luca Cosentino: The Berkeley Entrepreneurship Association is meant to be the one-stop shop for entrepreneurship at Berkeley. Ideally, everything that happens around entrepreneurship should be coordinated or monitored by the BEA. It’s not just for business school, but also for students across the campus. It’s the umbrella under which all entrepreneurship initiatives, partners, mentors, funding, and resources will rest. The BEA has been at Berkeley for a while as a collaborative effort, and it did a great job before, but we are adding to it. Prior to this relaunch, the BEA focused on one-off events and bringing founders to school. They did a great job regarding inspiring people to entrepreneurship. We want to keep doing what they did—the education side—but add the practical side. In this sense, the innovation is massive.We are rebranding BEA. We are moving from one-off events to something that the potential to be around for twenty years and could be translated into a core university program matching what the University currently offers on entrepreneurship.The one thing I want to underline is that is that every university has entrepreneurship programs where you’re matched with other people, but the value here is that we’re connecting people from different schools around the community of entrepreneurship. We are working to build the entrepreneurial community at Berkeley. The value of this community is that it won’t be agnostic to one specific initiative but will serve as an umbrella for all.MM: Why is the BEA important and what is its goal? LC: Before getting started with BEA, I spoke to a number of people from different business schools around the country. I wanted to know how each school dealt with entrepreneurship and how it was defined. What I noticed was that there were a bunch of great resources for helping students understand what entrepreneurship is, but it was really hard to find programs that helped students move from zero to one—from a basic idea to “Okay, let me try.” Students have access to many great initiatives where they can brainstorm and talk about their ideas, but to move from an idea to start effectively doing something around that idea is a completely different story.We believe that if we give business students all the weapons and tools they need to start working from day zero, it’s going to have a massive impact on everyone’s career.We also noticed that, too often, schools separate skills. For example, the computer science department is separated from the data scientist group and the information group. But we all know that entrepreneurship, great ideas, and great companies come from different skill sets, backgrounds, and diverse teams. We want to encourage that.A student’s life is busy. Their schedule is packed, so going out and finding people that you like and that you want to work with that are aligned with your ideas is pretty difficult. We want to make this process faster. We believe that this is a great value we’re going to bring to students.The application of the BEA is very big and far-reaching. There’s a strong impact on entrepreneurship itself, but also for employers and students. We all know that employers are keener to hire people from an entrepreneurial background. There’s a definite advantage for companies who bring on employees who have gone through capitalist discovery, testing, etc. This program really offers 360 degrees of benefits.CA: What will the BEA offer?MM: As an organization, we have a few missions starting this year and moving into next year. Inside the Relaunch of the Berkeley Entrepreneurship Association The next focus for the BEA is to connect students with startups. There are many students and MBAs who are not 100 percent keen to start their own company but are curious about what it’s like. Our goal is to offer them a part-time experience, while in school, that offers them a unique chance to test their skills in a start-up environment.Part of this focus will also be to connect the startup ecosystem at Berkeley. That means connecting startups, accelerators, VCs, etc. Already, we have collaborations with many different communities including:Participating Clubs: Computer Science Undergrad Association (CSUA), Computer Science Graduate Association (CSGSA), FemTech, Mobile Developers at Berkeley, Data Science Society, Upsilon Pi Epsilon Computer Science Honor Society, and many more coming.Collaborations: Xoogler community (community of ex-Googlers), Google Launchpad, Startup Grind, Dorm Fund, Sutardja Center for Entrepreneurship, SkyDeck Startup Squad, Citris Foundry, Food Club, and more.