Electron transport through micro- and nano-structured materials has been the subject of intense research for decades; this research forms the basis of current electronics technology and the continuing dramatic improvements in miniaturisation and device performance. At the same time, electron flow within individual molecules is fundamental to a wide range of naturally-occurring chemical and biological processes: Chemical reactions between molecules occur when there is an energetically favourable path for electrons to flow, and important examples of charge transfer in biological molecules occur in photosynthesis and in mechanisms of DNA damage and repair. Therefore, developing the ability to measure charge and spin transport through individual molecules is an exciting field of basic nanoscience research that lies at the interface between traditional areas of research in condensed matter physics and chemistry, with the potential to impact other areas such as molecular biology. Moreover, the ability to control electron flow through molecules holds promise for the creation of the next generation of technology; from the ultimate level of device miniaturisation (single-molecule device components) to ultrasensitive sensors and novel devices such as a quantum computer.
To measure electron transport through a single molecule it is necessary to connect to it at least two macroscopic leads. The measured conductance reflects not only the properties of the molecule itself, but, crucially, the nature of the electrode-molecule contacts. Precisely controlling the electrical contacts to a single molecule has proven to be an extremely difficult challenge, resulting in dramatic variations in experimental results and large discrepancies between experiment and theory. In this project, the student will obtain reproducible conductance measurements of simple, but extremely well characterised single-molecule junctions using a new approach where individual organic molecules are attached to semiconductor surfaces and probed using scanning tunnelling microscopy (STM) and spectroscopy (STS). The student will collaborate with theoreticians within the LCN and at the Universities of Sydney and Newcastle in Australia. Measurement facilities include four cryogenic ultrahigh vacuum STM systems capable of measuring with atomic-resolution at temperatures between 1.6 – 1000 Kelvin, and in a vectorable magnetic field of up to 6 Tesla. This range of capabilities is unique within the UK.
Funding Notes
Applicants should be highly motivated and have gained (or expect to gain) a first or upper second class honours degree (or equivalent) in physics, chemistry or materials science. This is a demanding experimental research project and therefore laboratory or research experience is highly desirable.
This project will be supervised by Dr Steven Schofield, an EPSRC research fellow in the London Centre for Nanotechnology and the School of Physical Sciences and Astronomy at University College London. Please direct informal enquiries to s.schofield@ucl.ac.uk, quoting reference SRS/04/10.
Please quote 10 Academic Resources Daily in your application to this opportunity!
