Mechanisms of Enhanced Optical Absorption for Ultrathin Silicon Solar Microcells with an Integrated Nanostructured Backside Reflector
Abbreviated Journal Title
ACS Appl. Mater. Interfaces
light trapping; photovoltaics; optical nanostructures; PHOTOVOLTAIC APPLICATIONS; CRYSTALLINE SILICON; PLASMONIC MATERIALS; CELLS; DESIGN; ADHESION; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary
This paper investigates mechanisms of enhanced light absorption exhibited by ultrathin Si solar microcells integrated with a periodically nanostructured, semitransparent metallic reflector. This backside reflector comprises periodic nanoscale relief features formed by soft-imprint lithography with a thin (similar to 35 nm) coating of Au. The work shows that microcells placed in direct contact above the nanostructured reflector's surface creates Fabry-Perot cavities, which traps impinging light inside the Si slab via the excitation of cavity modes. Experimental measurements show that the short-circuit current and efficiency values for devices incorporating this thin, semitransparent backside reflector outperform similar Si microcells integrated with a planar thick (similar to 300 nm) opaque mirror by similar to 10-15% because of enhanced absorption. Computational modeling that is supported by experimental measurements reveal that the dominant methods of enhancement stem from a complex interplay between backside diffraction/scattering and Fabry-Perot resonances. These same data demonstrate that plasmonic interactions contribute minimally to the optical enhancements seen.
Acs Applied Materials & Interfaces
"Mechanisms of Enhanced Optical Absorption for Ultrathin Silicon Solar Microcells with an Integrated Nanostructured Backside Reflector" (2013). Faculty Bibliography 2010s. 3832.