Effects of indirect bandgap top cells in a monolithic cascade cell structureThe effect of having a slightly indirect top cell in a three junction cascade monolithic stack is calculated. The minority carrier continuity equations are utilized to calculate individual junction performance. Absorption coefficient curves for general III-V compounds are calculated for a variety of direct and indirect gap materials. The results indicate that for a small excursion into the indirect region, (about 0.1 eV), the loss of efficiency is acceptably small (less than 2.5 percent) and considerably less than attempting to make the top junction a smaller direct bandgap.
Document ID
19840040200
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Curtis, H. B. (NASA Lewis Research Center Cleveland, OH, United States)
Godlewski, M. P. (NASA Lewis Research Center Cleveland, OH, United States)