Skin-like self-assembled monolayers on InAs / GaSb superlattice photodetectors
Journal of Physics D : Applied Physics
0022-3727 (print)1361-6463 (online)
IOP Institute of Physics Publishing
365102-1 - 365102-5
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Please cite this item using this persistent URLhttp://hdl.handle.net/11693/21328
We report on the effects of monolayer (ML) thick skin-like octadecanethiol (ODT, CH 3[CH 2] 17SH) 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 77K under 100mV bias. The zero bias responsivity and detectivity were 1.04AW 1 and 2.15 × 10 13 Jones, respectively, at 4μm and 77K. The quantum efficiency was determined to be 37% for a cutoff wavelength of 5.1μm.