Optimization of 3-junction inverted metamorphic solar cells for high-temperature and high-concentration operation

Four different band gap combinations of triple-junction inverted metamorphic solar cells are characterized as a function of temperature and concentration up to 120°C and ∼1000 suns. We demonstrate that the standard 1.82/1.40/1.00 eV combination is an excellent choice for typical operating conditions of 1000 suns and 75°C. Improved metal grids and thermal management in such a cell has achieved 42.6% efficiency at 327 suns and 40.9% at 1093 suns at 25°C.