Understanding the electronic properties of tunnel junctions which incorporate a nanometer-thick organic insulator remains a fundamental issue for molecular electronics. Covalent grafting of a densely-packed monolayer of n-alkyl saturated chains to Si(111) surfaces provides MIS tunnel junctions (metal / OML / semiconductor) which can be easily tuned : n or p doping of Si, insulating chain length and coverage, chemical functionality of the chains at the top metal interface.
Electronic properties of MIS tunnel junctions Hg // OML - Si (111) were characterized in static (current-voltage) and dynamic (admittance) modes. The interpretation of transport mechanisms and dipolar relaxation relies on modeling the characteristics measured as a function of temperature and applied voltage. Dynamic studies of defects and disorder of molecular chains grafted to crystalline Si surfaces are analyzed with multiscale models.
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- Dynamics of substituted alkyl monolayers covalently bonded to silicon: a broadband admittance spectroscopy study, C. GODET, A.B. FADJIE-DJOMKAM, S. ABABOU-GIRARD, S. TRICOT, P. TURBAN, Y. LI, S.P. PUJARI, L. SCHERES, H. ZUILHOF, B. FABRE, Journal of Physical Chemistry C 118, 6773–6787 (2014).
- Dielectric relaxation properties of carboxylic acid-terminated n-alkyl monolayers tethered to Si(111) : dynamics of dipoles and gauche defects, C. GODET, Journal of Physics: Condensed Matter 28, 094012 (2016).