Skin-like self-assembled monolayers on InAs/GaSb superlattice photodetectors

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Salihoglu O., Muti A., Kutluer K., Tansel T., TURAN R., AYDINLI A.

JOURNAL OF PHYSICS D-APPLIED PHYSICS, vol.45, no.36, 2012 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 45 Issue: 36
  • Publication Date: 2012
  • Doi Number: 10.1088/0022-3727/45/36/365102
  • Journal Indexes: Science Citation Index Expanded, Scopus


We report on the effects of monolayer (ML) thick skin-like octadecanethiol (ODT, CH3[CH2](17)SH) on type-II InAs/GaSb MWIR photodetectors. Circumventing the ageing effects of conventional sulfur compounds, we use ODT, a self-assembling, long molecular chain headed with a sulfur atom. Photodiodes coated with and without the self-assembled monolayer (SAM) ODT were compared for their electrical and optical performances. For ODT-coated diodes, the dark current density was improved by two orders of magnitude at 77 K under -100 mV bias. The zero bias responsivity and detectivity were 1.04 A W (1) and 2.15 x 10(13) Jones, respectively, at 4 mu m and 77 K. The quantum efficiency was determined to be 37% for a cutoff wavelength of 5.1 mu m.