Gallium arsenide concentrator solar cells with highly stable metallization

The development of GaAs/AlGaAs double-heterostructure concentrator solar cells for space operation that are capable of surviving 5 min thermal excursions to temperatures well beyond 500 degrees C without significant degradation is presented. The cells are formed epitaxially using the organometallic chemical vapor deposition growth process. The design utilizes a contact system that yields high stability at elevated temperature, and AM0 efficiency of up to 20% has been obtained with this approach. The efficiency is observed to change by less than 10% after a 5 min excursion to temperatures as high as 700 degrees C. Stability at higher temperatures and for longer times is discussed, and a comparison is made to the stability of conventional concentrator cells characterized by AM0 efficiencies of up to 23%.