%0 Journal Article %T Near‐Infrared Inorganic/Organic Optical Upconverter with an External Power Efficiency of >100% %A Chen, Jun %A Ban, Dayan %A Helander, Michael G. %A Lu, Zheng‐Hong %A Poole, Philip %J Advanced Materials %V 22 %N 43 %P 4900-4904 %@ 0935-9648 %D 2010-11-16 %I Wiley Subscription Services, Inc., A Wiley Company %~ DeepDyve