title: Tailoring Electrical Transport Across Metal-Thermoelectric Interfaces Using a Nanomolecular Monolayer.
abstract: We report a 13-fold increase in electrical contact conductivity Σc upon introducing a 1,8-octanedithiol (ODT) monolayer at Cu-Bi2Te3 interfaces. In contrast introducing ODT at Ni-Bi2Te3 interfaces results in a 20% decrease in Σc. Rutherford backscattering spectrometry, X-ray diffraction and electron spectroscopy analyses indicate that metal-sulfur and sulfur-Bi2Te3 bonds at metal-Bi2Te3 interfaces inhibit chemical mixing, curtail metal-telluride formation, and suppress oxidation. Suppressing p-type Cu2Te favors electrical transport across Cu-metallized n-type Bi2Te3, whereas inhibiting the formation of Ohmic-contact-promoting NixTey compromises the electrical conductance at Ni-Bi2Te3 interfaces. Our findings illustrate that molecular nanolayers could be attractive for manipulating interface chemistry and phase formation for tailoring electrical transport across metal-thermoelectric interfaces for solid-state refrigeration applications.
authors: 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: Thomas
authors: T
authors: Cardinal
authors: 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: Devender
authors: 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: Theodorian
authors: T
authors: Borca-Tasciuc
authors: 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: Ganpati
authors: G
authors: Ramanath
keywords: contact conductivity; diffusion barrier; interface chemistry; phase formation; self-assembled monolayers; thermoelectrics