erc: who: Atwater, H. A. what: Four-Junction Solar Cell with 40% Target Efficiency Fabricated by Wafer Bonding and Layer Transfer: Final Technical Report, 1 January 2005 - 31 December 2007 when: 20081101 where: https://digital.library.unt.edu/ark:/67531/metadc898332/ erc-support: who: University of North Texas Libraries what: Permanent: Stable Content: when: 20081203 where: https://digital.library.unt.edu/ark:/67531/