1. a US Army Materials Technology Laboratory, Materials Research Branch, Emerging Materials DWision , Watertown , Massachusetts , 02172-0001 , U.S.A.
2. d Department of Electrical Engineering , Solid State Group, Rutgers University , Piscataway , New Jersey , 08855-0909 , U.S.A.
3. b Fairleigh Dickinson University, Department of Electrical Engineering , Teaneck , New Jersey , 07666 , U.S.A.
4. c Hughes Aircraft Company , P.O. Box 92919 Airport Station, Los Angeles , California , 90009 , U.S.A.
5. e Exciton Science, Inc. , 10681 Perrin Drive, Garden Grove , California , 92640 , U.S.A.