High efficiency multijunction solar cells: Overview of important developments

The idea that a multi-junction solar cell can achieve high efficiency has a long history, dating back to 1957. However the actual realization of efficient multi-junction solar cells that demonstrate the advantages predicted by the early studies, has taken approximately 30 years. Currently there is cause for optimism and considerable efforts are underway to bring highly efficient multi-junction solar cells to terrestrial concentrator systems. This paper will provide an overview of important developments of high efficiency multi junction solar cells over the last decade.