My current interests are centred primarily around the characterisation of devices and systems using scanning probe microscopes, and understanding the influence of those measurement techniques on the devices under study.  Through greater understanding of these detrimental interaction processes it will be possible to de-couple the measurement interactions and get a lot more information about device growth, operation, performance and failure.

With other members of staff in the multidisciplinary nanotechnology centre (MNC) we have developed a technique of powered-sample scanning tunnelling microscopy (STM), where samples are studied with STM whilst operating and emitting light.  This technique offers a unique ability to study defect evolution on the surface of real operating devices, and to characterise the operation of novel device structures.

Other research interests include understanding and improving the growth of self-templated polymer films, towards well-ordered self-assembled photonic bandgap materials, and optoelectronic coatings.

I currently hold a joint Royal Academy of Engineering / Engineering and Physical Sciences Research Council fellowship.

Open PhD positions

I currently have two vacant PhD positions, details of which are available here.  Full EPSRC funding of course fees and stipend is available to EU/UK students.  If you are interested in this area of research and believe you satisfy the entry requirements for a PhD, please get in touch with me.

Funding is also available for overseas students via the School’s Zienkiewicz Scholarship fund, however competition for this fund is EXTREMELY tough.  Successful overseas candidates normally have a first class degree from a recognised university, a masters, some publications and at least IELTS 7.  If you satisfy most of these criteria and are interested in this area of research, then please get in contact with me.  The closing deadline for the next round of applications to the Zienkiewicz Scholarship is 14th May 2010.

Selected Publications

Pre-prints are available.  Please email for details.

•  R. J. Cobley, K. S. Teng, M. R. Brown, P. Rees and S. P. Wilks, “Surface defects in semiconductor lasers studied with cross-sectional scanning tunneling microscopy”, submitted to Applied Surface Science as part of the 6th International Workshop on Semiconductor Surface Passivation, Poland.
• R. J. Cobley, P. Rees, K. S. Teng and S. P. Wilks, “Analyzing real-time surface modification of operating semiconductor laser diodes using cross-sectional scanning tunneling microscopy”, J. Appl. Phys. (accepted, in press). 

• T. G. G. Maffeis, M. W. Penny, R. J. Cobley, E. Comini, G. Sberveglieri and S. P. Wilks, “XPS Characterisation of Vacuum Annealed Nanocrystalline WO3 Films” e-Journal of Surface Science and Nanotechnology 7, 319 (2009).

• M. P. Ackland, P. R. Dunstan, M. R. Brown, K. S. Teng, S. P. Wilks and R. Cobley, “Characterisation of the influence of multi-quantum barrier reflectors within GaInP/AlGaInP quantum well lasers using near-field imaging techniques”, Applied Surface Science 255 (3) 649-652 (2008)
• R. J. Cobley, K. S. Teng, M. R. Brown, S. P. Wilks and P. Rees, "Direct real-time observation of catastrophic optical degradation in operating semiconductor lasers using scanning tunneling microscopy”, Appl. Phys. Lett. 91,081119 (2007).
• M. R. Brown, P. Rees, R. J. Cobley, K. S. Teng, S. P. Wilks and A. Hughes, "The Effect of Interface Roughness on Multi-Layer Hetero-Structures”,  J. Appl. Phys 102, 113711 (2007).
• R. J. Cobley, K. S. Teng, M. R. Brown and S. P. Wilks, "Cross-sectional scanning tunneling microscopy of biased semiconductor lasers", J. Appl. Phys. 102, 086714 (2007).
• M. R Brown, R. J. Cobley, K.S. Teng, P. Rees, S. P. Wilks, A. Sobiesierski, P. M. Smowton and P. Blood, "Modeling multiple quantum barrier effects and reduced electron leakage in red-emitting laser diodes”, J. Appl. Phys. 100, 084509 (2006).
• R. J. Cobley, K. S. Teng, T. G. G. Maffeïs and S. P. Wilks, "Cross-sectional scanning tunneling microscopy and spectroscopy of strain in buried heterostructure lasers”, Surf. Sci. 600, 2857-2859 (2006).
• K. S. Teng, R. J. Cobley, M. R. Brown, S. P. Wilks and P. R. Dunstan, "Investigation on (Al0.7Ga0.3)(0.5)In0.5P/(Al0.3Ga0.7)(0.5)In0.5P multi-quantum-barrier superlattice using cross-sectional scanning tunneling microscopy”, J. App. Phys. 98, 033525 (2005). 
• R. J. Cobley, K. S. Teng, M. R. Brown, T. G. G. Maffeïs and S. P. Wilks, "Cross-sectional scanning tunneling microscopy of buried heterostructure lasers”, Int. J. Nanoscience 3, 525-531 (2004).

Links

• Royal Academy of Engineering
• EPSRC
• Multidisciplinary Nanotechnology Centre
• MNC Device Imaging Section