IMPROVED HIGH EFFICIENCY p-p-n GaAlAs-GaAs-GaAs SOLAR CELLS
Original Publication Date: 1989-Sep-01
Included in the Prior Art Database: 2005-Jan-28
Current p-p-n GaAlAs-GaAs-GaAs solar cells operate at AMI efficiencies of 21-22%. The theoretical limit for this cell is 27-28%. A major loss component is a low quantum efficiency for converting photons into current in the 2.5-3.2 eV region of the solar spectrum. This is shown in Fig. 1 which shows the spectral response of a state-of-the-art cell. Even though this is considered to be a "good" cell, further improvement is desired for concentrator applications where the cost of generating power is limited by the efficiency of the cell rather than its cost. Therefore, the 5-6 percentage points improvement which are theoretically possible are worthwhile achieving.