Regarding its 4-junction inverted metamorphic (4J IMM) solar cell, NREL announced demonstration of 45.7% conversion efficiency at 234 suns concentration. Multijunction cell is designed for operation in concentrator photovoltaic (CPV) systems where it is possible to receive 1,000+ suns of concentrated sunlight. Efficacy is enabled due to effective control and confinement of dislocations, broadband 4-layer AR coating, metamorphic tunnel junction interconnect, and GaInP top cell performance.