Localized Graphitization on Diamond Surface as a Manifestation of Dopants. Issue 42 (6th September 2021)

• Record Type: Journal Article
• Authors: Catalan, Francesca Celine I.; Anh, Le The; Oh, Junepyo; Kazuma, Emiko; Hayazawa, Norihiko; Ikemiya, Norihito; Kamoshida, Naoki; Tateyama, Yoshitaka; Einaga, Yasuaki; Kim, Yousoo
• Is Part Of: Advanced materials. Volume 33:Issue 42(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-09-06
• Subjects: boron‐doped diamond -- dopant effects -- graphitization -- surface morphology; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202103250
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Doped diamond electrodes have attracted significant attention for decades owing to their excellent physical and electrochemical properties. However, direct experimental observation of dopant effects on the diamond surface has not been available until now. Here, low‐temperature scanning tunneling microscopy is utilized to investigate the atomic‐scale morphology and electronic structures of (100)‐ and (111)‐oriented boron‐doped diamond (BDD) electrodes. Graphitized domains of a few nanometers are shown to manifest the effects of boron dopants on the BDD surface. Confirmed by first‐principles calculations, local density of states measurements reveal that the electronic structure of these features is characterized by in‐gap states induced by boron‐related lattice deformation. The dopant‐related graphitization is uniquely observed in BDD (111), which explains its electrochemical superiority over the (100) facet. These experimental observations provide atomic‐scale information about the role of dopants in modulating the conductivity of diamond, as well as, possibly, other functional doped materials. Abstract : Atomic‐scale imaging and spectroscopy of boron‐doped diamond (BDD) film electrodes reveal localized dopant‐induced surface graphitization. This work presents the first experimental demonstration of dopant effects on the surface morphology of doped diamond and explains the role of boron in the formation of density of states in BDD and the strong crystallographic orientation dependence of its electrochemical activity.