Atomic-scale imaging of insulating diamond through resonant electron injection

• Published in: Nature (London) Vol. 413; no. 6856; pp. 616 - 619
• Main Authors: Mayne, Andrew J, Dujardin, Gérald, Bobrov, Kirill
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 11-10-2001; Nature Publishing Group
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Crystals; Diamonds; Electron, positron and ion microscopes, electron diffractometers and related techniques; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Electrons; Exact sciences and technology; Injection; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Insulation; Materials science; Materials testing; Methods of materials testing and analysis; Physics; Scientific imaging; Tunneling; Electronic properties; Diamonds; Tunnel effect; Insulating materials; Surface analysis; Experimental study; Electron microscopy; IV characteristic; STM
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/35098053

The electronic properties of insulators such as diamond are of interest not only for their passive dielectric capabilities for use in electronic devices, but also for their strong electron confinement on atomic scales. However, the inherent lack of electrical conductivity in insulators usually prevents the investigation of their surfaces by atomic-scale characterization techniques such as scanning tunnelling microscopy (STM). And although atomic force microscopy could in principle be used, imaging diamond surfaces has not yet been possible. Here, we demonstrate that STM can be used in an unconventional resonant electron injection mode to image insulating diamond surfaces and to probe their electronic properties at the atomic scale. Our results reveal striking electronic features in high-purity diamond single crystals, such as the existence of one-dimensional fully delocalized electronic states and a very long diffusion length for conduction-band electrons. We expect that our method can be applied to investigate the electronic properties of other insulating materials and so help in the design of atomic-scale electronic devices.