{"413971":{"#nid":"413971","#data":{"type":"news","title":"Trees Used to Create Recyclable, Efficient Solar Cell","body":[{"value":"\u003Cp\u003EGeorgia Institute of Technology and Purdue University researchers have developed efficient solar cells using natural substrates derived from plants such as trees. Just as importantly, by fabricating them on cellulose nanocrystal (CNC) substrates, the solar cells can be quickly recycled in water at the end of their lifecycle. The technology is published in the journal Scientific Reports, the latest open-access journal from the Nature Publishing Group.\u003C\/p\u003E\u003Cp\u003EGeorgia Tech College of Engineering Professor Bernard Kippelen led the study and says his team\u2019s project opens the door for a truly recyclable, sustainable and renewable solar cell technology.\u003C\/p\u003E\u003Cp\u003EThe researchers report that the organic solar cells reach a power conversion efficiency of 2.7 percent, an unprecedented figure for cells on substrates derived from renewable raw materials. The CNC substrates on which the solar cells are fabricated are optically transparent, enabling light to pass through them before being absorbed by a very thin layer of an organic semiconductor. During the recycling process, the solar cells are simply immersed in water at room temperature. Within minutes, the CNC substrate dissolves and the solar cell can be separated easily into its major components.\u003C\/p\u003E\u003Cp\u003E\u201cThe development and performance of organic substrates in solar technology continues to improve, providing engineers with a good indication of future applications,\u201d said Kippelen, who is also the director of Georgia Tech\u2019s Center for Organic Photonics and Electronics (COPE). \u201cBut organic solar cells must be recyclable. Otherwise we are simply solving one problem \u2013 less dependence on fossil fuels \u2013 while creating another \u2013 a technology that produces energy from renewable sources but is not disposable at the end of its lifecycle.\u201d\u003C\/p\u003E\u003Cp\u003ETo date, organic solar cells have been typically fabricated on glass or plastic. Neither is easily recyclable, and petroleum-based substrates are not very eco-friendly. For instance, if cells fabricated on glass were to break during manufacturing or installation, the useless materials would be difficult to dispose of. Paper substrates are better for the environment, but have shown limited performance because of high surface roughness or porosity. However, cellulose nanomaterials made from wood are green, renewable and sustainable. The substrates have a low surface roughness of only about two nanometers.\u003C\/p\u003E\u003Cp\u003E\u201cOur next steps will be to work toward improving the power conversion efficiency over 10 percent, levels similar to solar cells fabricated on glass or petroleum-based substrates,\u201d said Kippelen. The group plans to achieve this by optimizing the optical properties of the solar cell\u2019s electrode.\u003C\/p\u003E\u003Cp\u003EPurdue School of Materials Engineering associate professor Jeffrey Youngblood collaborated with Kippelen on the research. A provisional patent on the technology has been filed with the U.S. Patent Office.\u003C\/p\u003E\u003Cp\u003EThere is another positive impact of using natural products to create cellulose nanomaterials. The nation\u2019s forest product industry projects that tens of millions of tons of them could be produced once large-scale production begins, potentially in the next five years.\u003C\/p\u003E\u003Cp\u003EThe research is the latest project by COPE, which studies the use and development of printed electronics. Last year the center created the first completely plastic solar cell.\u003C\/p\u003E\u003Cp class=\u0022BlocktextSmall\u0022\u003E\u003Cem\u003EThis research was funded in part through the Center for Interface Science: Solar Electric Materials, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001084 (Y.Z., J.S., C.F., A.D.), by the Air Force Office of Scientific Research (Grant No. FA9550-09-1-0418) (J. H.), by the Office of Naval Research (Grant No. N00014-04-1-0313) (T.K., B.K.), and the U.S. Department of Agriculture \u2013Forest Service (Grant No. 12-JV-11111122-098). Funding for CNC substrate processing was provided by USDA-Forest Service (Grant No. 11-JV-11111129-118) (R.J.M., J.P.Y., J.L.). The authors thank Rick Reiner and Alan Rudie from the U.S. Forest Service- Forest Products Laboratory (FPL) for providing CNC mate\u003C\/em\u003E\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"GA Tech and Purdue University develop and efficient solar cell derived from plants"}],"uid":"27178","created_gmt":"2015-06-11 13:25:32","changed_gmt":"2016-10-08 03:18:37","author":"Amna Jamshad","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2013-06-01T00:00:00-04:00","iso_date":"2013-06-01T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"413961":{"id":"413961","type":"image","title":"Bernard Kippelen","body":null,"created":"1449254239","gmt_created":"2015-12-04 18:37:19","changed":"1475895147","gmt_changed":"2016-10-08 02:52:27","alt":"Bernard Kippelen","file":{"fid":"202426","name":"130329_kippelen_0.jpg","image_path":"\/sites\/default\/files\/images\/130329_kippelen_0_0.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/images\/130329_kippelen_0_0.jpg","mime":"image\/jpeg","size":31115,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/130329_kippelen_0_0.jpg?itok=U2fOdIW9"}},"413951":{"id":"413951","type":"image","title":"Solar cell made from trees , photograph of a solar cell fabricated at Georgia Tech on nanocellulose substrates derived from trees. Photo courtesy of Canek Fuentes-Hernandez","body":null,"created":"1449254239","gmt_created":"2015-12-04 18:37:19","changed":"1475895147","gmt_changed":"2016-10-08 02:52:27","alt":"Solar cell made from trees , photograph of a solar cell fabricated at Georgia Tech on nanocellulose substrates derived from trees. Photo courtesy of Canek Fuentes-Hernandez","file":{"fid":"202425","name":"130329_kippelen.jpg","image_path":"\/sites\/default\/files\/images\/130329_kippelen_1.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/images\/130329_kippelen_1.jpg","mime":"image\/jpeg","size":7993,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/130329_kippelen_1.jpg?itok=DEQwrReM"}}},"media_ids":["413961","413951"],"groups":[{"id":"372221","name":"Renewable Bioproducts Institute (RBI)"}],"categories":[{"id":"132","name":"Institute Leadership"},{"id":"133","name":"Special Events and Guest Speakers"},{"id":"134","name":"Student and Faculty"},{"id":"8862","name":"Student Research"},{"id":"144","name":"Energy"},{"id":"145","name":"Engineering"},{"id":"154","name":"Environment"},{"id":"149","name":"Nanotechnology and Nanoscience"},{"id":"135","name":"Research"}],"keywords":[{"id":"4754","name":"IPST"},{"id":"93811","name":"RBI"},{"id":"128751","name":"recyclable"},{"id":"4174","name":"renewable"},{"id":"169729","name":"solar cell"},{"id":"128731","name":"tree"}],"core_research_areas":[{"id":"39441","name":"Bioengineering and Bioscience"},{"id":"39531","name":"Energy and Sustainable Infrastructure"},{"id":"39471","name":"Materials"},{"id":"39501","name":"People and Technology"},{"id":"39491","name":"Renewable Bioproducts"}],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EKelly B. 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