PhD Studentship: Defect Studies in CVD Diamond: Production, Identification and Exploitation of New Defects

University of Warwick

Project description:
It has been known for over 15 years that homoepitaxial diamond can be synthesised by chemical vapour deposition (CVD) with very high purity (residual nitrogen and boron impurities less than 1 part per billion), but typically this material contains high concentrations of dislocations (>104 dislocations cm-2). The strain resulting from dislocations and dislocation bundles, as well as point defects, is undesirable for many quantum and optical technologies.

Furthermore it is known that High Pressure High Temperature (HPHT) synthesis of single crystal diamond from a transition metal solvent can, with careful selection of the seed crystal and precise control of the temperature and pressure, produce material with a much lower dislocation and stacking fault density in (100) growth sectors (-2) over areas exceeding 25 mm2. However in HPHT synthetic diamond the incorporation of nitrogen and boron impurities varies dramatically between different growth sectors but even with the use of additives in the solvent (e.g. Ti, Al) to “getter” the nitrogen, the nitrogen impurity levels are not believed to be as low as those observed in the best CVD diamonds. Furthermore, boron is a persistent impurity in HPHT diamond.

It has been shown that if sufficient care is taken in the selection and preparation of the HPHT diamond substrate and in the initial stages of CVD growth, the number of dislocations can be dramatically reduced (-2) in the homoepitaxially overgrown CVD material over areas of order 10 mm2, whilst still retaining high purity. However, many applications that require both high purity and low strain also demand areas. At the moment such samples are not available primarily because of the lack of large high quality single growth sector single crystal substrates.

This project will focus on:

  • (i) Characterisation of the defects in CVD diamond available commercially. This work will impact on the identification of material produced for Gem applications.
  • (ii) Via collaboration with the several growers we will focus on the characterisation of CVD diamond grown in such a way to minimise the incorporation of point and extended defects. Such work with contribute to the production of higher quality diamond for a variety of photonic and quantum applications.
  • (iii) Study of diamonds implanted with short lived radioactive ions to facilitate the production and identification of new defects not attainable by in situ doping or traditional ion implantation.

This project is part of the EPSRC Centre for Doctoral Training in Diamond Science and Technology (www.DST-DTC.ac.uk) and includes a specially-designed one year MSc course at the University of Warwick which also includes two MSc mini-projects at HRD Antwerp and CERN. These mini-projects relate to the PhD project.

This project is suitable for a student with a background in the physical sciences and the successful applicant will have a minimum of a 2:1 first degree in a relevant discipline/subject area.

For further details please contact Prof Mark Newton: M.E.Newton@warwick.ac.uk

Group website go.warwick.ac.uk/diamond

Funding: The DST CDT provides funding for the 4 year programme to UK and EU students (non-UK EU students must have resided in the UK for three years prior to the start of their course in order to be eligible).

These 4 year studentships pay a stipend to cover maintenance as well as paying the university fees and provide funding for mini-project, PhD travel expenses and research support. The stipends are at the standard research council rates (for 2018/19 that is £14,777 per annum).

Share this PhD
     
  Share by Email   Print this job   More sharing options
We value your feedback on the quality of our adverts. If you have a comment to make about the overall quality of this advert, or its categorisation then please send us your feedback
Advert information

Type / Role:

PhD

Location(s):

Midlands of England