Diamond Sensors for Extreme Environments:
From the laboratory to the Ocean
Abstract
Diamond, a wide band gap semiconductor with superlative electronic properties, can be readily doped p-type with boron enabling a wide range of high performance electronic devices to be realized, including field-effect transistors. Further, diamond is chemically resilient, whilst its surface can be readily chemically functionalized, has an extremely ‘wide’ electrochemical window, and is transparent at optical wavelengths. Diamond has also been shown to resist biofouling in marine environments. This leads to the idea that diamond may be an ideal platform for sensors destined for use in extreme environments, including ocean deployment. That high quality single crystal diamond grown by laboratory methods is now a commercially available material at modest cost, it is timely to explore its use in just such a context.
The Diamond Electronics Group (DEG) at UCL has been working on the science and technology of multifunctional diamond sensors for extreme applications for several years. This paper will considered two distinct types of diamond sensor, those based on electronic signals, as compared to optical sensor technology. In the former case, multi-functional diamond water sensors (combined pH, p[O2], electrical conductivity and temperature) have been designed and fabricated that can be operated at high pressures (and high pressure boundaries) and temperatures. These combine Ion-Sensitive (ISFET) and electrochemical elements for their operation. For trace detection of chemicals within an aquatic environment, Surface-enhanced Raman Spectroscopy (SERS) can be used typical SERS substrates are far too fragile for ocean deployment, but we have shown that Au nanoparticles embedded in a diamond matrix can offer high sensitivity to a wide range of chemical species whilst remaining robust throughout prolonged periods of use. Involving multinational industrial partners, the journey from scientific work in the laboratory to the realization of sensors suited for extreme environment applications will be discussed.
Brief Biography
Prof. Richard Jackman holds UCLs Chair in Electronic Devices and heads UCLs Diamond Electronics Group (DEG) whose laboratories are within the London Centre for Nanotechnology. Richard moved to UCL in 1988, having previously held the Royal Society Eliz. Challenor Research Fellowship at the University of Oxford, to establish one of the first teams dedicated to studying the electronic properties of the then newly emerging material, diamond, grown by chemical vapour deposition (CVD) methods. Since then UCLs DEG has been responsible for licensing some of the first diamond device technology to reach commercial development by industry and has published patents relating to such. The group enjoys an international reputation and having published more than 250 journal articles relating to diamond technology, Richard regularly presents papers at the major conferences in the field. Pertinent to the current conference, Richard is currently heading a > $ 2M 4-year programme, funded by BAE Systems, relating to Diamond Sensor Technology for use in extreme environments. Professor Jackman is a Fellow of both the IET and IoP.
