Development of MOVPE grown GaSb-on-GaAs interfacial misfit solar cells

• Published in: Journal of applied physics 2023-06, Vol.133 (24)
• Main Authors: Kessler-Lewis, Emily S., Polly, Stephen J., Nelson, George T., Slocum, Michael A., Pokharel, Nikhil, Ahrenkiel, Phil, Hubbard, Seth M.
• Format: Article
• Language: English
• Subjects: Applied physics; Carrier lifetime; Diffusion length; Dislocation density; Epitaxial growth; Gallium antimonides; Gallium arsenide; Minority carriers; Molecular beam epitaxy; Open circuit voltage; Photovoltaic cells; Solar cells; Threading dislocations; Vapor phase epitaxy; Vapor phases
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/5.0141163

GaSb grown on GaAs through interfacial misfit (IMF) arrays grown via molecular beam epitaxy has been heavily studied; there is limited research, however, on IMF growth through metal-organic vapor phase epitaxy. To demonstrate viability for integration in a multijunction solar cell for terrestrial use, it is imperative to demonstrate high quality GaSb grown on GaAs through metal-organic vapor phase epitaxy. The preferred gallium precursors for n-type and p-type GaSb for longest minority carrier diffusion length were determined to be trimethylgallium and triethylgallium, respectively. A heteroepitaxial GaSb-on-GaAs device attained an open-circuit voltage of 190 mV and an efficiency of 2.2%. Extracted threading dislocation density from the minority carrier lifetime for the heteroepitaxial GaSb-on-GaAs device was determined to be 7.5 × 10 6 cm − 2. In a modeled multijunction solar cell, this device attributes to an overall efficiency of 33.1% under AM1.5g illumination.