Researchers at the Fraunhofer Institute for Solar Energy Systems ISE, using a new antire-flection coating, have successfully increased the efficiency of the best four-junction solar cell to date from 46.1% to 47.6% at a concentration of 665 suns. This is a global milestone, as there is currently no solar cell with a higher efficiency worldwide. The results are presented at the 2nd International tandemPV Workshop, taking place in Freiburg, Ger-many. For the last two years, Fraunhofer ISE has b...