Optical characterization of electronic transitions arising from the Au/S interface of self-assembled n-alkanethiolate monolayers
✍ Scribed by J. Shi; B. Hong; A.N. Parikh; R.W. Collins; D.L. Allara
- Book ID
- 103030709
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 349 KB
- Volume
- 246
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
Analyses of optical frequency ellipsometric spectra obtained in situ upon completion of the self-assembly of n-alkanethiolate monolayers on gold substrates immersed in methanol reveal the presence of a 1.2 + 0.4 A thick S/Au interface layer. This layer exhibits unique optical transitions, modeled as two Lorentzian oscillators with imaginary parts peaked at = 570 nm ( = 2.2 eV) and ---290 nm ( = 4.3 eV), indicating a perturbation of the near-surface gold electronic structure upon thiol chemisorption. A further, more rigorous, spectral analysis involving an anisotropic, uniaxially oriented chain assembly reveals the presence of significant microscopic void defects in the otherwise densely packed monolayers.