title: Multifold Electrical Conductance Enhancements at Metal-Bismuth Telluride Interfaces Modified Using an Organosilane Monolayer.
abstract: Controlling electrical transport across metal-thermoelectric interfaces is key to realizing high efficiency devices for solid state refrigeration and waste-heat harvesting. We obtain up to 17-fold increases in electrical contact conductivity Σcby inserting a mercaptan-terminated organosilane monolayer at Cu-Bi2Te3and Ni-Bi2Te3interfaces, yielding similar Σcfor both metals by offsetting an otherwise 7-fold difference. The Σcimprovements are underpinned by silane-moiety-induced inhibition of Cu diffusion, promotion of high-conductivity interfacial nickel telluride formation, and mercaptan-induced reduction of Bi2Te3surface oxides. Our findings should enable incorporating nanomolecular layers with appropriately chosen terminal moieties in thermoelectric device metallization schemes without metal diffusion barriers.
authors.affiliation: Department of Materials Science and Engineering and ‡Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.
authors.forename: Thomas
authors.identifier: http://orcid.org/0000-0002-8192-4082
authors.initials: T
authors.lastname: Cardinal
authors.affiliation: Department of Materials Science and Engineering and ‡Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.
authors.forename: Matthew
authors.identifier: http://orcid.org/0000-0001-6119-3828
authors.initials: M
authors.lastname: Kwan
authors.affiliation: Department of Materials Science and Engineering and ‡Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.
authors.forename: Theodorian
authors.initials: T
authors.lastname: Borca-Tasciuc
authors.affiliation: Department of Materials Science and Engineering and ‡Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.
authors.forename: Ganpati
authors.initials: G
authors.lastname: Ramanath
keywords: contact conductivity; diffusion barrier; interface chemistry; phase formation; self-assembled monolayers; surface oxide reduction; thermoelectrics