Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Engineers are developing an optical “nanocavity” to boost light absorption in semiconductors; it could improve solar cells, cameras and more

A rendering shows a beam of light interacting with an optical nanocavity. The nanocavity boosts light absorption in ultrathin semiconductors.  Credit: Advanced Materials
A rendering shows a beam of light interacting with an optical nanocavity. The nanocavity boosts light absorption in ultrathin semiconductors.

Credit: Advanced Materials

Abstract:
Associated with unhappy visits to the dentist, "cavity" means something else in the branch of physics known as optics.

Engineers are developing an optical “nanocavity” to boost light absorption in semiconductors; it could improve solar cells, cameras and more

Buffalo, NY | Posted on February 26th, 2014

Put simply, an optical cavity is an arrangement of mirrors that allows beams of light to circulate in closed paths. These cavities help us build things like lasers and optical fibers used for communications.

Now, an international research team pushed the concept further by developing an optical "nanocavity" that boosts the amount of light that ultrathin semiconductors absorb. The advancement could lead to, among other things, more powerful photovoltaic cells and faster video cameras; it also could be useful for splitting water using energy from light, which could aid in the development of hydrogen fuel.

The team, comprised of faculty and students from the University at Buffalo and two Chinese universities, presented its findings Feb. 24 in the journal Advanced Materials. The paper, called "Nanocavity enhancement for ultra-thin film optical absorber," is available here: http://bit.ly/1bGGIbO.

"We're just scratching the surface, but the preliminary work that we've done is very promising," said Qiaoqiang Gan, PhD, lead author and UB assistant professor of electrical engineering. "This advancement could lead to major breakthroughs in energy-harvesting and conversion, security and other areas that will benefit humankind."

Semiconductors form the basis of modern electronics. They work by manipulating the flow of energy in electronic devices. The most common semiconductor material, silicon, is used to make microchips for cellular phones, computers and other electronic devices.

Industry has kept pace with the demand for smaller, thinner and more powerful optoelectronic devices, in part, by shrinking the size of the semiconductors used in these devices.

The problem, however, is that these ultrathin semiconductors do not absorb light as well as conventional bulk semiconductors. Therefore, there is an intrinsic tradeoff between the ultrathin semiconductors' optical absorption capacity and their ability to generate electricity.

As a result, researchers worldwide are trying to find ways to boost the amount of light that ultrathin semiconductors can absorb. Harvard University researchers recently had varying degrees of success by combining thin films of germanium, another common semiconductor, on a gold surface.

"While the results are impressive, gold is among the most expensive metals," said Suhua Jiang, associate professor of materials science at Fudan University in China. "We illustrated a nanocavity, made with aluminum or other whitish metals and alloys that are far less expensive, can be used to increase the amount of light that semiconducting materials absorb."

The nanocavity consists of, from bottom to top: aluminum, aluminum oxide and germanium. In the experiment, light passed through the germanium, which is 1.5 to 3 nanometers thick, and circulated in a closed path through the aluminum oxide and aluminum.

The absorption rate peaked at 90 percent, with germanium absorbing roughly 80 percent of the blue-green light and aluminum absorbing the rest. This is ideal, said Haomin Song, PhD candidate in electrical engineering at UB and the paper's first author, because the bulk of the light stays within the semiconducting material.

"The nanocavity has many potential applications. For example, it could help boost the amount of light that solar cells are able to harvest; it could be implanted on camera sensors, such as those used for security purposes that require a high-speed response. It also has properties that could be useful for photocatalytic water splitting, which could help make hydrogen fuel a reality," Song said.

Before any of that happens, however, more research must be done, especially as it relates to how the semiconductor would turn the light into power as opposed to heat.

Gan's research group is collaborating with Alexander Cartwright, PhD, UB professor of electrical engineering and vice president for research and economic development, and Mark Swihart, PhD, UB professor of chemical and biological engineering, to develop ultrathin energy-harvesting devices.

Gan is also working with Hao Zeng, PhD, UB associate professor of physics, to study its effect on photocatalysis.

In addition to Gan, Jiang and Song, the paper's other authors are: UB PhD candidates in electrical engineering Dengxin Ji, Kai Liu, Xie Zeng and Nan Zhang; Luqing Guo and Zhejun Liu, both PhD candidates at Fudan; and Haifeng Hu, assistant professor at Northeastern University in China.

The National Science Foundation supported the research.

Gan is a member of UB's electrical engineering optics and photonics research group, which includes Cartwright, professors Edward Furlani and Pao-Lo Liu; associate professor Natalia Litchinitser; and assistant professor Liang Feng.

The group carries out research in nanophotonics, biophotonics, hybrid inorganic/organic materials and devices, nonlinear and fiber optics, metamaterials, nanoplasmonics, optofluidics, microelectromechanical systems (MEMS), biomedical microelectromechanical systems (BioMEMs), biosensing and quantum information processing.

####

For more information, please click here

Contacts:
Cory Nealon

716-645-4614

Copyright © University at Buffalo

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Bosch announces high-performance MEMS acceleration sensors for wearables June 27th, 2017

Nanometrics to Participate in the 9th Annual CEO Investor Summit 2017: Accredited investor and publishing research analyst event held concurrently with SEMICON West and Intersolar 2017 in San Francisco June 27th, 2017

NMRC, University of Nottingham chooses the Quorum Q150 coater for its reliable and reproducible film thickness when coating samples with iridium June 27th, 2017

Picosun’s ALD solutions enable novel high-speed memories June 27th, 2017

Chip Technology

Nanometrics to Participate in the 9th Annual CEO Investor Summit 2017: Accredited investor and publishing research analyst event held concurrently with SEMICON West and Intersolar 2017 in San Francisco June 27th, 2017

New TriboLab CMP Provides Cost-Effective Characterization of Chemical Mechanical Wafer Polishing Processes: Bruker Updates Industry-Standard CP-4 Platform for Most Flexible and Reliable Testing June 27th, 2017

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Research accelerates quest for quicker, longer-lasting electronics: UC Riverside-led research makes topological insulators magnetic well above room temperatures June 25th, 2017

Discoveries

Physicists make quantum leap in understanding life's nanoscale machinery June 27th, 2017

Picosun’s ALD solutions enable novel high-speed memories June 27th, 2017

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Research accelerates quest for quicker, longer-lasting electronics: UC Riverside-led research makes topological insulators magnetic well above room temperatures June 25th, 2017

Announcements

Bosch announces high-performance MEMS acceleration sensors for wearables June 27th, 2017

Nanometrics to Participate in the 9th Annual CEO Investor Summit 2017: Accredited investor and publishing research analyst event held concurrently with SEMICON West and Intersolar 2017 in San Francisco June 27th, 2017

NMRC, University of Nottingham chooses the Quorum Q150 coater for its reliable and reproducible film thickness when coating samples with iridium June 27th, 2017

Picosun’s ALD solutions enable novel high-speed memories June 27th, 2017

Energy

Tiny bubbles provide tremendous propulsion in new microparticles research-Ben-Gurion U. June 21st, 2017

Enhanced photocatalytic activity by Cu2O nanoparticles integrated H2Ti3O7 nanotubes June 21st, 2017

Cambridge Nanotherm partners with Inabata for global sales and distribution June 20th, 2017

Development of low-dimensional nanomaterials could revolutionize future technologies June 15th, 2017

Photonics/Optics/Lasers

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

New carbon nitride material coupled with ruthenium enhances visible-light CO2 reduction in water June 15th, 2017

Changing the color of laser light on the femtosecond time scale: How BiCoO3 achieves second harmonic generation June 14th, 2017

Learning with light: New system allows optical “deep learning”: Neural networks could be implemented more quickly using new photonic technology June 12th, 2017

Solar/Photovoltaic

Tiny bubbles provide tremendous propulsion in new microparticles research-Ben-Gurion U. June 21st, 2017

Enhanced photocatalytic activity by Cu2O nanoparticles integrated H2Ti3O7 nanotubes June 21st, 2017

Development of low-dimensional nanomaterials could revolutionize future technologies June 15th, 2017

In a project funded by the Austrian Science Fund FWF, the physicist Serdar Sarıçiftçi investigates possible uses in electronics of the semiconductor properties of indigo pigment June 14th, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project