Comparative study of electrical properties of metal-monolayer-semiconductor junctions at macro and nano scales | Posted on:2008-04-01 | Degree:M.Sc | Type:Thesis | University:Simon Fraser University (Canada) | Candidate:Kuikka, Marcus Aleksander | Full Text:PDF | GTID:2441390005963041 | Subject:Chemistry | Abstract/Summary: | | The electrical properties of metal-monolayer-semiconductor junctions were examined at the macroscale using mercury drop and thermally evaporated gold pad electrodes, and at the nanoscale using ballistic emission electron microscopy (BEEM) and high-resolution transmission electron microscopy (TEM). Oxide-free silicon wafers were modified with n-alkyl or o-functionalized monolayers prepared via organometallic or thermal reactions. The mercury-molecule-silicon junctions displayed a clear dependence of the barrier height on both chain length and terminal functional groups of the monolayer. Measurements using thermally deposited gold contacts (i.e., gold/monolayer/silicon) yielded identical barrier heights for all monolayers, indicating that the gold atoms penetrated into the molecular layer causing a shorting of the junctions. BEEM and TEM studies showed uniform penetration of the gold atoms into the monolayer at the nanoscale. It was evident that thiol-functionalized monolayers are able to inhibit gold penetration, preserving an intact organic monolayer at the metal-semiconductor interface.Keywords: Silicon monolayer interface contact BEEM Hg I-V Au I-V molecular electronics... | Keywords/Search Tags: | Monolayer, Junctions, BEEM, Gold | | Related items |
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