Enhanced Thermopower of Saturated Molecules by Noncovalent Anchor-Induced Electron Doping of Single-Layer Graphene Electrode

Autor:	Hwa Rang Kim, Byung Hee Hong, Hyo Jae Yoon, Sohyun Park, Juhee Kim
Rok vydání:	2021
Předmět:	Materials science Graphene Mechanical Engineering Fermi level Self-assembled monolayer Thermoelectric materials law.invention symbols.namesake Mechanics of Materials Chemical physics law Seebeck coefficient Thermoelectric effect Monolayer symbols General Materials Science Raman spectroscopy
Zdroj:	Advanced materials (Deerfield Beach, Fla.). 33(41)
ISSN:	1521-4095
Popis:	Enhancing thermopower is a key goal in organic and molecular thermoelectrics. Herein, it is shown that introducing noncovalent contact with a single-layer graphene (SLG) electrode improves the thermopower of saturated molecules as compared to the traditional gold-thiolate covalent contact. Thermoelectric junction measurements with a liquid-metal technique reveal that the value of Seebeck coefficient in large-area junctions based on n-alkylamine self-assembled monolayers (SAMs) on SLG is increased up to fivefold compared to the analogous junction based on n-alkanethiolate SAMs on gold. Experiments with Raman spectroscopy and field-effect transistor analysis indicate that such enhancements benefit from the creation of new in-gap states and electron doping through noncovalent interaction between the amine anchor and the SLG electrode, which leads to a reduced energy offset between the Fermi level and the transport channel. This work demonstrates that control of interfacial bonding nature in molecular junctions improves the Seebeck effect in saturated molecules.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2abc4211bd9ec6e590da69afcdada12e https://pubmed.ncbi.nlm.nih.gov/34453364 Zobrazit plný text záznamu Plný text