GaSb-Based Solar Cells for Full Solar Spectrum Energy Harvesting

5 years ago

GaSb-Based Solar Cells for Full Solar Spectrum Energy Harvesting

Kenneth J. Schmieder, John A. Rogers, Mitchell F. Bennett, Shawn Mack, Matthew P. Lumb, Matthew Meitl, Kyu-Tae Lee, Robert J. Walters, María González, Scott Burroughs, Brent Fisher, David Scheiman

In this work, a multijunction solar cell is developed on a GaSb substrate that can efficiently convert the long-wavelength photons typically lost in a multijunction solar cell into electricity. A combination of modeling and experimental device development is used to optimize the performance of a dual junction GaSb/InGaAsSb concentrator solar cell. Using transfer printing, a commercially available GaAs-based triple junction cell is stacked mechanically with the GaSb-based materials to create a four-terminal, five junction cell with a spectral response range covering the region containing >99% of the available direct-beam power from the Sun reaching the surface of the Earth. The cell is assembled in a mini-module with a geometric concentration ratio of 744 suns on a two-axis tracking system and demonstrated a combined module efficiency of 41.2%, measured outdoors in Durham, NC. Taking into account the measured transmission of the optics gives an implied cell efficiency of 44.5%. In this work, a mechanically stacked multijunction solar cell which encompasses the spectral range containing more than 99% of the available power from the direct-beam terrestrial solar spectrum is demonstrated. A mini-module constructed using the cell produces an efficiency of 41.2%, measured outdoors. This implies an outdoor cell efficiency of 44.5% when taking into account the transmission of the optics.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/aenm.201700345