GaP ZnS for Blue Light Emitting Diodes

AstroPower is developing a two-junction monolithic tandem solar cell composed of (AlxGa1-x)0.51In.49P lattice matched to GaAs for use as the top cell in a three-junction, two-terminal tandem stack. This tunable bandgap material system is capable of current matching, at 2.03eV, in a two-junction monolithic tandem solar cell two terminal design of (AlxGa1-x)0.51In0.49P/GaAs yielding a best case predicted efficiency of 27.2 %. This solar cell can in turn be applied as a current matched top cell on a triple-junction, two-terminal configuration with silicon solar cells with a predicted efficiency of 34.1%. The Al-Ga-In-P material system can also be useful for integration of sensor arrays, monolithic LED displays, or optical computing systems as well as ultra-bright green LED and laser technology with a bandgap as high as 2.3 eV.