Creating Graphene p–n Junctions Using Self-Assembled Monolayers

• Published in: ACS applied materials & interfaces Vol. 4; no. 9; pp. 4781 - 4786
• Main Authors: Sojoudi, Hossein, Baltazar, Jose, Tolbert, Laren M, Henderson, Clifford L, Graham, Samuel
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 26.09.2012
• Subjects: self-assembled monolayers (SAMs); p−n junction; interface modification; thermally stable doping; graphene
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/am301138v

3-Aminopropyltriethoxysilane (APTES) and perfluorooctyltriethoxysilane (PFES) were used to modify the interface between transferred CVD graphene films and its supporting dielectric to create n-type and p-type graphene, respectively. A graphene p–n junction was obtained by patterning both modifiers on the same dielectric and verified through the creation of a field effect transistor (FET). Characteristic I–V curves indicate the presence of two separate Dirac points which confirms an energy separation of neutrality points within the complementary regions. This method minimizes doping-induced defects and results in thermally stable graphene p–n junctions for temperatures up to 200 °C.