Advanced photovoltaic concentrator cells. Quarterly technical progress report, September 1, 1980-November 30, 1980. [AlGaAs/AlGaSb]

It is the objective of this project to demonstrate the technical feasibility of producing monolithic stacked multibandgap solar cells having 30% conversion efficiency at 30/sup 0/C and 25% conversion efficiency at 150/sup 0/C under 500 to 1000 SUNs AM2 illumination. To meet this objective, the following tasks will be performed: 1) grow and optimize single junction AlGaAs cells having bandgaps of 1.6 eV and 1.7 eV and AlGaSb cells having bandgaps of 0.95 eV and 1.1 eV; 2) develop techniques for joining these optimized single junction cells by means of non-lattice matched intercell ohmic contacts having sufficient optical transparency combined with low electrical and thermal resistance to meet the overall performance objective; and 3) characterize performance of the individual cells and stacked combinations using appropriate light and dark I-V and spectral response measurements over the operating temperature range of 30 to 200/sup 0/C and for illumination levels of 1 to 1000 SUNs AM2. Progress is reported. (WHK)