Electronic Structures and Nanofilm Growth of 2,7-Dioctyl[1]Benzothieno[3,2-b]Benzothiophene on Black Phosphorus

J Nanosci Nanotechnol. 2018 Jun 1;18(6):4332-4336. doi: 10.1166/jnn.2018.15044.

Abstract

The interfacial electronic structure and morphology of nanofilm of 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene (C8-BTBT) on black phosphorus (BP) was investigated with photoemission spectroscopy (PES) and atomic force microscopy (AFM). The heterojunction of C8-BTBT/BP is a straddling one with a hole injection barrier of 1.41 eV and electron injection barrier of 2.43 eV from BP to C8-BTBT. There is a 0.18 eV interface dipole pointing from BP to C8-BTBT, which means a relative weak interaction of substrate BP and the C8-BTBT molecules. Volmer-Weber growth mode of C8-BTBT nanofilm on BP was confirmed and the C8-BTBT molecules adopt standing up configuration.