1. 40% efficient metamorphic GaInP∕GaInAs∕Ge multijunction solar cells
2. Solar cell efficiency tables (Version 38)
3. P. R. Sharps, A. Cornfeld, M. Stan, A. Korostyshevsky, V. Ley, B. Cho, T. Varghese, J. Diaz, and D. Aiken, in 33rd IEE Photovoltaic Specialists Conference (Institute of Electrical and Electronics Engineers (IEEE), San Diego, CA, 2008), pp. 1.