Enhanced Optical Absorption and Spectral Photocurrent in a-Si:H by Single- and Double-Layer Silver Plasmonic Interfaces


Saleh Z. M. , NASSER H., ÖZKOL E., GÜNÖVEN M., ALTUNTAS B., BEK A. , ...More

PLASMONICS, vol.9, no.2, pp.357-365, 2014 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 9 Issue: 2
  • Publication Date: 2014
  • Doi Number: 10.1007/s11468-013-9632-9
  • Title of Journal : PLASMONICS
  • Page Numbers: pp.357-365

Abstract

Single and double plasmonic interfaces consisting of silver nanoparticles embedded in media with different dielectric constants including SiO2, SiNx, and Al:ZnO have been fabricated by a self-assembled dewetting technique and integrated to amorphous silicon films. Single plasmonic interfaces exhibit plasmonic resonances whose frequency is red-shifted with increasing particle size and with the thickness of a dielectric spacer layer. Double plasmonic interfaces consisting of two different particle sizes exhibit resonances consisting of double minima in the transmittance spectra. The optical extinction of a-Si:H deposited on these interfaces is broadened into the red indicating higher absorption and/or scattering at wavelengths higher than those typically absorbed by a-Si:H without plasmonic interfaces. While the photocurrent shows an overall decrease for the samples with the interfaces, significant enhancement of photocurrent is observed near the low-energy edge of the bandgap (600-700 nm). These results correlate well with the broadened extinction spectra of the interfaces and are interpreted in terms of enhanced absorption in that region.