Low-cost solution processing method developed for CIGS-based solar cellsJuly 08, 2009The method could provide an answer to a manufacturing issue Though the solar industry today predominately produces solar panels made from crystalline silicon, they remain relatively expensive to make. New players in the solar industry have instead been looking at panels that can harvest energy with CIGS (copper-indium-gallium-selenide) or CIGS-related materials. CIGS panels have a high efficiency potential, may be cheaper to produce and would use less raw materials than silicon solar panels. But unfortunately, manufacturing of CIGS panels on a commercial scale has thus far proven to be difficult. Recently researchers at the UCLA Henry Samueli School of Engineering and Applied Science have developed a low-cost solution processing method for CIGS-based solar cells that could provide an answer to the manufacturing issue. In a new study to be published in the journal Thin Solid Films on July 7, Yang Yang, a professor in the school's Department of Materials Science and Engineering, and his research team show how they have developed a low-cost solution processing method for their copper-indium-diselenide solar cells which have the potential to be produced on a large scale. "This CIGS-based material can demonstrate very high efficiency," said William Hou, a graduate student on Yang's team and first author of the study. "People have already demonstrated efficiency levels of up to 20 percent, but the current processing method is costly. Ultimately the cost of fabricating the product makes it difficult to be competitive with current grid prices. However, with the solution process that we recently developed, we can inherently reach the same efficiency levels and bring the cost of manufacturing down quite significantly." The copper-indium-diselenide thin-film solar cell developed by Yang's team achieved 7.5 percent efficiency in the published study but has in a short amount of time already improved to 9.13 percent in the lab. "We started this process 16 months ago from ground zero. We spent three to four months getting the material to reach 1 percent and today it's around 9 percent. That is about an average increase of 1 percent every two months," said Yang, also a member of the California NanoSystems Institute, where some of the work is being done. Currently, most CIGS solar cells are produced using vacuum evaporation techniques called co-evaporation, which can be costly and time-consuming. The active elements - copper, indium, gallium and selenide - are heated and deposited onto a surface in a vacuum. Using vacuum processing to create CIGS films with uniform composition on a large scale has also been challenging. The copper-indium-diselenide material created by Yang's team does not need to go through the vacuum evaporation process. Their material is simply dissolved into a liquid, applied and baked. To prepare the solution, Yang's team used hydrazine as the solvent to dissolve copper sulfide and indium selenide in order to form the constituents for the copper-indium-diselenide material. In solar cells, the "absorber layer" (either copper-indium-diselenide or CIGS) itself is the most critical to performance and the most difficult to control. Their copper-indium-diselenide layer, which is in solution form, can be easily painted or coated evenly onto a surface and baked. "In our method, material utilization is one advantage. Another advantage is our solution technology has the potential to be fabricated in a continuous roll-to-roll process. Both are important breakthroughs in terms of cost," said Hou. The team's goal is to reach an efficiency level of 15 to 20 percent. Yang predicts three to four years before commercialization. "As we continue to work on enhancing the performance and efficiency of the solar cells, we also look forward to opportunities to collaborate with industry in order to develop this technology further. We hope this technology will lead to a new green energy company in the U.S., especially here in California so that it may also bring job opportunities to many who need it," said Yang. University of California - Los Angeles |
|||||||||||||||||||||
| Related Solar Cells Current Events and Solar Cells News Articles Understanding mechanical properties of silicon nanowires paves way for nanodevices Silicon nanowires are attracting significant attention from the electronics industry due to the drive for ever-smaller electronic devices, from cell phones to computers. Vibrations key to efficiency of green fluorescent protein University of California, Berkeley, chemists have discovered the secret to the success of a jellyfish protein whose green glow has made it the darling of biologists and the subject of the 2008 Nobel Prize in Physiology or Medicine. Chemists describe solar energy progress and challenges, including the 'artificial leaf' Scientists are making progress toward development of an "artificial leaf" that mimics a real leaf's chemical magic with photosynthesis - but instead converts sunlight and water into a liquid fuel such as methanol for cars and trucks. Toward better solar cells: Chemists gain control of light-harvesting paths University of Florida chemists have pioneered a method to tease out promising molecular structures for capturing energy, a step that could speed the development of more efficient, cheaper solar cells. Switzerland has sent its first satellite into space The Indian launcher Polar Space Launch Vehicle took off at 8:22 a.m. - Swiss time. Twenty minutes later, the SwissCube was ejected from the nose cone of the rocket at an altitude of around 720 kilometers. Engineers Produce 'How-To' Guide for Controlling the Structure of Nanoparticles Tiny objects known as nanoparticles are often heralded as holding great potential for future applications in electronics, medicine and other areas. Looking deeply into polymer solar cells Researchers from the Eindhoven University of Technology and the University of Ulm have made the first high-resolution 3D images of the inside of a polymer solar cell. Carbon nanotubes could make efficient solar cells Using a carbon nanotube instead of traditional silicon, Cornell researchers have created the basic elements of a solar cell that hopefully will lead to much more efficient ways of converting light to electricity than now used in calculators and on rooftops. Gold Solution for Enhancing Nanocrystal Electrical Conductance In a development that holds much promise for the future of solar cells made from nanocrystals, and the use of solar energy to produce clean and renewable liquid transportation fuels, researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have reported a technique by which the electrical conductivity of nanorod crystals of the semiconductor cadmium-selenide was increased 100,000 times. Light at the speed of a bicycle and much more The speed of light, 300 million metres per second, was long thought an immutable constant and has defined our understanding of matter and energy but recent research in the area of optics and photonics is proving that we can manipulate light to some ingenious and hugely lucrative ends. More Solar Cells Current Events and Solar Cells News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||