Mechanisms of enhanced optical absorption for ultrathin silicon solar microcells with an integrated nanostructured backside reflector

Christopher J. Corcoran, Somi Kang, Lanfang Li, Xiaoying Guo, Debashis Chanda, Ralph G. Nuzzo

Research output: Contribution to journalArticle

Abstract

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 (∼35 nm) coating of Au. The work shows that microcells placed in direct contact above the nanostructured reflector's surface creates Fabry-Pérot 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 (∼300 nm) opaque mirror by ∼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-Pérot resonances. These same data demonstrate that plasmonic interactions contribute minimally to the optical enhancements seen.

Original languageEnglish (US)
Pages (from-to)4239-4246
Number of pages8
JournalACS Applied Materials and Interfaces
Volume5
Issue number10
DOIs
StatePublished - May 22 2013

Keywords

  • light trapping
  • optical nanostructures
  • photovoltaics

ASJC Scopus subject areas

  • Materials Science(all)

Fingerprint Dive into the research topics of 'Mechanisms of enhanced optical absorption for ultrathin silicon solar microcells with an integrated nanostructured backside reflector'. Together they form a unique fingerprint.

  • Cite this