{"242351":{"#nid":"242351","#data":{"type":"event","title":"Georgia Tech-COPE Distinguished Lecture Series - Karl Leo","body":[{"value":"\u003Cp\u003EProfessor Karl Leo from the Institute of Applied Photophysics at the Dresden University of Technology\u0026nbsp;\u0026nbsp;(Dreseden, Germany)\u0026nbsp;visits Georgia Tech and presents a lecture as part of the\u0026nbsp;\u003Ca href=\u0022http:\/\/cope.gatech.edu\/events\/lecture\/\u0022\u003EGeorgia Tech-COPE Distinguished Lecture Series\u003C\/a\u003E.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003E\u003Cem\u003E\u0022Recent Progress in Organic Solar Cells:\u0026nbsp;From a Lab Curiosity to a Serious Photovoltaic Technology\u0022\u003C\/em\u003E\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003ECarbon-based organic semiconductors have many potential advantages like easy large-area\u0026nbsp;preparation on flexible substrates, large variety of materials, and low cost. Although known for a century, organics have achieved little impact until OLED displays entered the market\u0026nbsp;about a decade ago, demonstrating that organic semiconductors are ready for significant\u0026nbsp;commercial markets.\u003C\/p\u003E\u003Cp\u003EIn contrast to light-emitting devices, organic solar cells have so far achieved little commercial\u0026nbsp;impact due to low efficiency and lifetime. However, organic solar cells have recently\u0026nbsp;achieved significant progress and have crossed the 10% efficiency mark. For a broad\u0026nbsp;application, further significant improvements are needed.\u003C\/p\u003E\u003Cp\u003EThis talk overviews the key features of solid-state organic solar cells\u0026nbsp;and recent developments in the field. One central research area is the design of the bulk\u0026nbsp;heterojunction active layer, requiring a nanoscale phase separation and optimized\u0026nbsp;morphology to achieve efficient operation. A key challenge of the field is to find design rules\u0026nbsp;which relate the molecular structure of absorber materials to layer morphology and cell\u0026nbsp;properties. The difficulty is that small changes of the molecular structure, leaving the\u0026nbsp;electronic properties of the individual molecule nearly unchanged, can lead to large changes\u0026nbsp;in the crystal packing and molecular orientation, causing significant differences in the\u0026nbsp;electronic properties in the active layer. Furthermore, I will discuss highly efficient tandem\u0026nbsp;structures with optimized electrical and optical properties. Very efficient recombination\u0026nbsp;contacts can be realized by n- and p-type doped transport layers. Structures based on these\u0026nbsp;approaches have reached efficiencies of 12% and have the potential to reach approximately\u0026nbsp;20%. Furthermore, these high-efficiency cells also show encouraging lifetimes.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EAbout Karl Leo\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EKarl Leo obtained the Diplomphysiker degree from the University of Freiburg in 1985, working\u0026nbsp;with Adolf Goetzberger at the Fraunhofer-Institut f\u00fcr Solare Energiesysteme. In 1988, he\u0026nbsp;obtained the PhD degree from the University of Stuttgart for a PhD thesis performed at the\u0026nbsp;Max-Planck-Institut f\u00fcr Festk\u00f6rperforschung in Stuttgart under supervision of Hans Queisser.\u0026nbsp;From 1989 to 1991, he was postdoc at AT\u0026amp;T Bell Laboratories in Holmdel, NJ, U.S.A. From\u0026nbsp;1991 to 1993, he was with the Rheinisch-Westf\u00e4lische Technische Hochschule (RWTH) in\u0026nbsp;Aachen, Germany. Since 1993, he is full professor of optoelectronics at the Technische\u0026nbsp;Universit\u00e4t Dresden, until 2013, he has been also working at the Fraunhofer-Institution for\u0026nbsp;Organics, Materials and Electronic Devices COMEDD. His main interests are novel\u0026nbsp;semiconductor systems like semiconducting organic thin films; with special emphasis to\u0026nbsp;understand basics device principles and the optical response. His work was recognized by the\u0026nbsp;following awards: Otto-Hahn-Medaille (1989), Bennigsen-F\u00f6rder-Preis (1991), Leibniz-Award\u0026nbsp;(2002), award of the Berlin-Brandenburg Academy (2002), Manfred-von-Ardenne-Preis (2006),\u0026nbsp;and Zukunftspreis of the German president (2011). He is cofounder of several companies,\u0026nbsp;including Novaled AG and Heliatek GmbH.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EKarl Leo from the Institute of Applied Photophysics at the Dresden University of Technology\u0026nbsp;\u0026nbsp;(Dreseden, Germany)\u0026nbsp;visits Georgia Tech and presents a lecture entitled,\u0026nbsp;\u003Cem\u003E\u0022Recent Progress in Organic Solar Cells:\u0026nbsp;From a Lab Curiosity to a Serious Photovoltaic Technology\u0022,\u003C\/em\u003E\u003Cstrong\u003E\u0026nbsp;\u003C\/strong\u003Eas part of the Georgia Tech-COPE Distinguished Lecture Series.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Karl Leo from the Institute of Applied Photophysics at the Dresden University of Technology"}],"uid":"27185","created_gmt":"2013-10-03 11:35:29","changed_gmt":"2017-04-13 21:24:00","author":"Jason Martin","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2014-02-07T15:00:00-05:00","event_time_end":"2014-02-07T15:00:00-05:00","event_time_end_last":"2014-02-07T15:00:00-05:00","gmt_time_start":"2014-02-07 20:00:00","gmt_time_end":"2014-02-07 20:00:00","gmt_time_end_last":"2014-02-07 20:00:00","rrule":null,"timezone":"America\/New_York"},"extras":["free_food"],"hg_media":{"245991":{"id":"245991","type":"image","title":"Karl Leo","body":null,"created":"1449243758","gmt_created":"2015-12-04 15:42:38","changed":"1475894921","gmt_changed":"2016-10-08 02:48:41","alt":"Karl Leo","file":{"fid":"197918","name":"leo.jpg","image_path":"\/sites\/default\/files\/images\/leo_0.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/images\/leo_0.jpg","mime":"image\/jpeg","size":294041,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/leo_0.jpg?itok=p1mGYaRM"}}},"media_ids":["245991"],"related_links":[{"url":"http:\/\/www.iapp.de\/iapp\/index.php?id=10001\u0026lan=de\u0026order=3;3","title":"Karl Leo, Institute of Applied Photophysics"}],"groups":[{"id":"1273","name":"Center for Organic Photonics and Electronics (COPE)"}],"categories":[],"keywords":[{"id":"918","name":"COPE"},{"id":"6153","name":"distinguished lecture series"},{"id":"77051","name":"karl leo"},{"id":"1692","name":"materials"},{"id":"6845","name":"opera"},{"id":"6594","name":"organic materials"},{"id":"953","name":"photovoltaics"},{"id":"167411","name":"solar cells"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1792","name":"Arts and Performance"}],"invited_audience":[{"id":"78751","name":"Undergraduate students"},{"id":"78761","name":"Faculty\/Staff"},{"id":"78771","name":"Public"},{"id":"174045","name":"Graduate students"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003ESharon Lawrence\u003C\/p\u003E\u003Cp\u003E404-894-4040\u003C\/p\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}