Prof William Gillin

William Gillin

Professor of Experimental Physics

School of Physical and Chemical Sciences
Queen Mary University of London
www.qmul.ac.uk/spcs/staff/academics/profiles/wgillin.html
Centre for Experimental and Applied Physics
Centre for Chemical Research

Research

Interests

William Gillin works primarily on the electrical and optical properties of organic materials. His primary research interests are in the area or organic lanthanide complexes for producing optical gain. He is also works with Paragraf Ltd on the use of vapour phase deposited graphene as a replacement for indium tin oxide in OLED devices and has a longstanding interest in organic spintronics.

Lanthanide ions, such as erbium, are widely used in optical amplifiers and lasers due to their long intrinsic lifetime which makes population inversion possible. However, this same property means that they are very poor at absorbing light so powerful pump sources, such as lasers, are required to make optical amplifiers work. By incorporating the ion into an organic host it is possible to excite the organic directly and then transfer the energy directly to the lanthanide ion; this is called sensitization. Using this approach it may be possible to replace the high power pump laser with low cost LEDs. We have developed novel fluorinated organic molecules that allow us to produce materials where the quantum efficiency of the erbium ions is >50% and which exhibit sensitization of a factor of ~10000. Using this approach we have demonstrated population inversion for the erbium ions in an organic layer deposited onto a silicon substrate when optically pumped from a low power light source. This technology has been patented and is the basis for a spin-out company Chromosol Ltd which Prof Gillin launched in 2017.

Organic spintronics is the control and manipulation of electronic spin on individual organic molecules within an organic electronic device. This technology can, for example, be used to produce devices that are highly sensitive to weak magnetic fields. We have a programme that works on producing organic spinvalves and understanding spin injection and extraction in these devices and the role of interfacial layers on controlling those processes. We also work on understanding the spin interactions that occur within devices such as organic light emitting diodes and organic photovoltaic cells. Controlling these processes is vital to improving device performance as many of the quenching mechanisms are highly spin dependent.