Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

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

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)
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)

Abstract:
High Precision Scribing of Thin Film Solar Cells by a Picosecond Laser

P.I.: Yung C. Shin, Gary Cheng (co-PI), Wenqian Hu,
Martin Yi Zhang, Seunghyun Lee

Purdue University

In this paper, the feasibility of thin-film solar cells scribing via a picosecond (ps) laser is investigated. The optical and thermal properties of thin films are studied first. Next, molybdenum and ZnO thin films are deposited on soda lime glass substrates by pulsed laser deposition. Then experiments for picosecond laser scribing are performed with different wavelengths and average powers and results are analyzed for process parameter optimization. The scribed slots are measured using a surface profilometer and a scanning electron microscope (SEM). Using the optimized laser parameters, the ablation depths of the slots are accurate within 0.1 μm tolerance, the edges are sharp without distortions and slot bottoms are flat. These slots are precisely machined with a high speed, which makes ps laser scribing of solar cells a promising technique.

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

West Lafayette, IN | Posted on March 8th, 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's 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 www.nrel.gov/learning/re_photovoltaics.html

####

For more information, please click here

Contacts:
Writer:
Emil Venere
765-494-4709


Sources:
Yung Shin
765-494-9775,


Gary Cheng
765-494-5436


Joshua Chamot
NSF media officer
703-292-7730

Copyright © Purdue University School of Mechanical Engineering

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

Scientific breakthrough in rechargeable batteries: Researchers from Singapore and Québec Team Up to Develop Next-Generation Materials to Power Electronic Devices and Electric Vehicles February 28th, 2015

First detailed microscopy evidence of bacteria at the lower size limit of life: Berkeley Lab research provides comprehensive description of ultra-small bacteria February 28th, 2015

Leti to Offer Updates on Silicon Photonics Successes at OFC in LA February 27th, 2015

Moving molecule writes letters: Caging of molecules allows investigation of equilibrium thermodynamics February 27th, 2015

Imaging

Renishaw and Bruker team up for a workshop on TERS and co-localised AFM Raman February 26th, 2015

Real-time observation of bond formation by using femtosecond X-ray liquidography February 26th, 2015

Bruker-Sponsored Sixth AFM BioMed Conference Highlights Increasing Impact of AFM in Biological Applications February 26th, 2015

Dendrite eraser: New electrolyte rids batteries of short-circuiting fibers: Solution enables a battery with both high efficiency & current density February 24th, 2015

Discoveries

First detailed microscopy evidence of bacteria at the lower size limit of life: Berkeley Lab research provides comprehensive description of ultra-small bacteria February 28th, 2015

Leti to Offer Updates on Silicon Photonics Successes at OFC in LA February 27th, 2015

Moving molecule writes letters: Caging of molecules allows investigation of equilibrium thermodynamics February 27th, 2015

Untangling DNA with a droplet of water, a pipet and a polymer: With the 'rolling droplet technique,' a DNA-injected water droplet rolls like a ball over a platelet, sticking the DNA to the plate surface February 27th, 2015

Announcements

Scientific breakthrough in rechargeable batteries: Researchers from Singapore and Québec Team Up to Develop Next-Generation Materials to Power Electronic Devices and Electric Vehicles February 28th, 2015

First detailed microscopy evidence of bacteria at the lower size limit of life: Berkeley Lab research provides comprehensive description of ultra-small bacteria February 28th, 2015

Leti to Offer Updates on Silicon Photonics Successes at OFC in LA February 27th, 2015

Moving molecule writes letters: Caging of molecules allows investigation of equilibrium thermodynamics February 27th, 2015

Tools

Hiden CATLAB Microreactor System at ARABLAB 2015 | Visit us on Booth 1011 February 26th, 2015

Renishaw and Bruker team up for a workshop on TERS and co-localised AFM Raman February 26th, 2015

Maximum Precision in 3D Printing: New complete solution makes additive manufacturing standard for microfabrication February 26th, 2015

Real-time observation of bond formation by using femtosecond X-ray liquidography February 26th, 2015

Energy

In quest for better lithium-air batteries, chemists boost carbon's stability: Nanoparticle coatings improve stability, cyclability of '3DOm' carbon February 25th, 2015

New nanowire structure absorbs light efficiently: Dual-type nanowire arrays can be used in applications such as LEDs and solar cells February 25th, 2015

Learning by eye: Silicon micro-funnels increase the efficiency of solar cells February 25th, 2015

Magnetic nanoparticles enhance performance of solar cells X-ray study points the way to higher energy yields February 25th, 2015

Photonics/Optics/Lasers

Leti to Offer Updates on Silicon Photonics Successes at OFC in LA February 27th, 2015

Rice's Stephan Link honored for nanoscience research: The Welch Foundation honors ‘rising star’ with $100,000 Hackerman Award February 26th, 2015

Maximum Precision in 3D Printing: New complete solution makes additive manufacturing standard for microfabrication February 26th, 2015

Learning by eye: Silicon micro-funnels increase the efficiency of solar cells February 25th, 2015

Solar/Photovoltaic

New nanowire structure absorbs light efficiently: Dual-type nanowire arrays can be used in applications such as LEDs and solar cells February 25th, 2015

Learning by eye: Silicon micro-funnels increase the efficiency of solar cells February 25th, 2015

Magnetic nanoparticles enhance performance of solar cells X-ray study points the way to higher energy yields February 25th, 2015

Researchers enable solar cells to use more sunlight February 25th, 2015

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







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE