Dense N delta doping by layer overgrowth onto a diamond (100) surface: Nitrogen and hydrogen distribution and retention

Title

Dense N delta doping by layer overgrowth onto a diamond (100) surface: Nitrogen and hydrogen distribution and retention

Speaker

Prof. Alon Hoffman (Technion, Chemistry)

Host

Prof. Kai Huang (GTIIT, Chemistry)

Time and Location

Apr. 26 2022, Tuesday, 4:00pm-5:00pm(China Time) or 11:00am-12:00pm(Israel Time),  E211 (Education Building, 2nd floor)

Language

English

Abstract

Negatively charged nitrogen-vacancy (NV^–) center in diamond is an important system for nanoscale biosensing, NV-based wide-field magnetic microscopy, etc. For such applications, the NV^– centers require to be within a few nanometers from the diamond surface. Recently, we demonstrated a new approach for creation of nanometer-thin dense delta-doped layer of NV^– centers in diamond by employing a pure nitridation stage using microwave plasma and a subsequent in situ diamond overgrowth. We achieved the highest nitrogen concentration in a delta-doped layer (1.8×10²⁰ atoms.cm–3) ever reported while maintaining the pristine diamond crystal quality. Also, investigated the influence of surface chemical and structural properties of initial nitrided diamond surfaces on the nitrogen and hydrogen distribution in the N delta layers fabricated onto diamond (100) surfaces by different surface nitridation methods followed by diamond overgrowth. Surface damage enhances hydrogen incorporation into the N delta layer. The nitrogen retention ratio efficiency in the delta layer depends on the crystallinity of the nitrided diamond surface and bonding: it is higher when nitrogen is bonded in the sub-surface region. An extensive secondary ion mass spectroscopic analysis of the N delta doped layer diamond will be presented.

Biography

Prof Alon Hoffman is a full professor at the Schulich faculty of Chemistry at the Technion and also holds the Joseph Szydlowsky Chair in Science.  Alon completed his D.Sc. in 1987 at the Technion investigating adsorption processes on single crystal metal alloy surfaces  by electron spectroscopy.   During the 2012-2016 he was Dean of the Schulich Faculty of Chemistry.  His research effort spans from basic to fundamental research in surface science and thin films  with more than 300 publication.  During the last thirty years Prof Hoffman’ research  has been related to different aspects associated to the chemical, physical and electronic properties of diverse carbon surfaces such as graphite, diamond and amorphous carbon.   In particular he has investigated very extensively the interaction of different molecules such as nitrogen, oxygen and oxygen  with single and poly crystalline diamond surfaces by surface electron spectroscopy including high resolution electron energy loss spectroscopy, X-ray photoelectron spectroscopy and NEXAFS.  He has also investigated the different processes involved in the formation – nucleation and growth- of polycrystalline diamond films by chemical vapor deposition onto non-diamond substrates.