Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ultrafast laser 'scribing' technique to cut cost, hike efficiency of solar cells

09.03.2011
Researchers are developing a technology that aims to help make solar cells more affordable and efficient by using a new manufacturing method that employs an ultrafast pulsing laser.

The innovation may help to overcome two major obstacles that hinder widespread adoption of solar cells: the need to reduce manufacturing costs and increase the efficiency of converting sunlight into an electric current, said Yung Shin, a professor of mechanical engineering and director of Purdue University's Center for Laser-Based Manufacturing.

Critical to both are tiny "microchannels" needed to interconnect a series of solar panels into an array capable of generating useable amounts of power, he said. Conventional "scribing" methods, which create the channels mechanically with a stylus, are slow and expensive and produce imperfect channels, impeding solar cells' performance.

"Production costs of solar cells have been greatly reduced by making them out of thin films instead of wafers, but it is difficult to create high-quality microchannels in these thin films," Shin said. "The mechanical scribing methods in commercial use do not create high-quality, well-defined channels. Although laser scribing has been studied extensively, until now we haven't been able to precisely control lasers to accurately create the microchannels to the exacting specifications required."

The researchers hope to increase efficiency while cutting cost significantly using an "ultrashort pulse laser" to create the microchannels in thin-film solar cells, he said.

The work, funded with a three-year, $425,000 grant from the National Science Foundation, is led by Shin and Gary Cheng, an associate professor of industrial engineering. A research paper demonstrating the feasibility of the technique was published in Proceedings of the 2011 NSF Engineering Research and Innovation Conference in January. The paper was written by Shin, Cheng, and graduate students Wenqian Hu, Martin Yi Zhang and Seunghyun Lee.

"The efficiency of solar cells depends largely on how accurate your scribing of microchannels is," Shin said. "If they are made as accurately as possibly, efficiency goes up."

Research results have shown that the fast-pulsing laser accurately formed microchannels with precise depths and sharp boundaries. The laser pulses last only a matter of picoseconds, or quadrillionths of a second. Because the pulses are so fleeting the laser does not cause heat damage to the thin film, removing material in precise patterns in a process called "cold ablation."

"It creates very clean microchannels on the surface of each layer," Shin said. "You can do this at very high speed, meters per second, which is not possible with a mechanical scribe. This is very tricky because the laser must be precisely controlled so that it penetrates only one layer of the thin film at a time, and the layers are extremely thin. You can do that with this kind of laser because you have a very precise control of the depth, to about 10 to 20 nanometers."

Traditional solar cells are usually flat and rigid, but emerging thin-film solar cells are flexible, allowing them to be used as rooftop shingles and tiles, building facades, or the glazing for skylights. Thin-film solar cells account for about 20 percent of the photovoltaic market globally in terms of watts generated and are expected to account for 31 percent by 2013.

The researchers plan to establish the scientific basis for the laser-ablation technique by the end of the three-year period. The work is funded through NSF¨Vs Civil Mechanical and Manufacturing Innovation division.

Information about photovoltaic cells is available from the U.S. Department of Energy's National Renewable Energy Laboratory at http://www.nrel.gov/learning/re_photovoltaics.html

Related websites:

Yung Shin:
https://engineering.purdue.edu/ME/People/ptProfile?id=12309
Gary Cheng:
https://engineering.purdue.edu/IE/People/profile?resource_id=34940
IMAGE CAPTION:
This image, taken with a scanning electron microscope, shows a microchannel that was created using an ultrafast-pulsing laser. (Purdue University School of Mechanical Engineering image/Yung Shin)

A publication-quality photo is available at http://www.purdue.edu/uns/images/2011/shin-solar.jpg

Abstract on the research in this research is available at: http://www.purdue.edu/newsroom/research/2011/110308ShinSolar.html

Emil Venere | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Process Engineering:

nachricht New technology for ultra-smooth polymer films
28.06.2018 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

nachricht Diamond watch components
18.06.2018 | Schweizerischer Nationalfonds SNF

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Air pollution leads to cardiovascular diseases

21.08.2018 | Ecology, The Environment and Conservation

Researchers target protein that protects bacteria's DNA 'recipes'

21.08.2018 | Life Sciences

A paper battery powered by bacteria

21.08.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>