"Measurement of Quantization Effects in Low Dimensional Diamond Systems by Scanning Tunneling Spectroscopy"

TYPESpecial Seminar - Solid State Institute, Technion
Speaker:Mr. Asaf Bolker,
Affiliation:Physics Department and Solid State Institute, Technion
Location:Solid State Auditorium(Entrance)
Remark:Ph.D. Student of Prof. Rafi Kalish and Dr. Cecile Saguy
Abstract:Diamond has regained new interest in recent years due to the unique optical properties of its color centers (such as the NV- center), the ability to control its conductivity by apply various terminations to its surface and the fact that it is a non-cytotoxic and biocompatible material. In addition diamond can be produced in the form of nano particles, paving the way to a variety of exciting applications ranging from easily positioned single photon sources to cell biomarkers and nanometric drug delivery platforms. However, the use of these low dimensional diamond systems and the development of new applications based on the quantum properties of diamond require a better understanding of their electronic properties.
In this work the electronic properties of low dimensional diamond systems are probed using scanning tunneling microscopy (STM) and spectroscopy (STS), which enable the measurement of the local density of state (LDOS) at sub-nanometer spatial resolution.
The discrete energy levels of the 2D quantum well formed by hydrogen termination and humidity exposure of bulk diamond surface are determined and found to be in good agreement with theory. In addition, the first experimental evidence of quantum confinement effects such as a widening of the band gap and Coulomb blockade effect in single isolated nano-diamonds is shown. Finally, the effect of hydrogen surface termination on nanodiamonds is studied as a function of their size.