The group's main interests have been in making optical measurements on wide-bandgap semiconductors and low-dimensional systems such as quantum dots, wires and wells.

Lasing from TEM modes in perovskite nanocrystals

Topics currently being investigated include the generation of single photons in the blue, coupling of quantum dot emission at telecom wavelengths to photonic crystals, coupling of various quantum emitters to discrete cavities and stimulated emission from nanocrystals and nanowires. Past work focussed on coherent electron-hole dynamics, excitonic dynamics in wide band gap materials such as GaN and InGaN, and gain mechanisms in bulk and quantum well lasers. Please have a look at our publication list for references to relevant recent work. 

Our work on nitride quantum dots, (more detail in the research tab), has been showcased on the Science and Engineering South website.

Until December 2009 we were part of the Quantum Information Processing IRC (QIPIRC), directed by Prof. Andrew Briggs at the Department of Materials in Oxford. We looked at InGaN quantum dots, studying dephasing, carrier lifetime and inter-dot interactions. We also work on dots made from InGaAs, which emits in the infrared. These dots are registered optically and then placed in cavities formed by using photonic bandgap structures, also as part of the IRC in quantum information processing.

The group worked on grant as part of the Materials World network in May 2010 jointly with Dr. Rachel Oliver's group at the Department of Materials, Cambridge University and Prof. Evelyn Hu at the School of Engineering and Applied Sciences, Harvard University. The title of the project is "Materials World Network to Optimize the Growth of InGaN Quantum Dots within High Quality Optical Micro-Cavities".

Photonic crystal SEM image

In April 2013 we started work on a new project in collaboration with Dr. Fred Brossard at Hitachi Cambridge Laboratories and Prof. Ray Murray at Imperial College, London. The title of the project was "Long wavelength single photon sources and dotonic molecules".

A project on non-polar InGaN quantum dots for single photon applications commenced in late February 2015. This was in collaboration with Dr. Rachel Oliver's group in the Materials Department in Cambridge. We have recently been working on a project jointly with the national University of Singapore on coupling single perovskite quantum dots to external cavities. 

Over the past 10 years we have collaborated with Prof. Youngin Park from Ulsan National Institute of Science and Technology on a range of projects involving two-dimensional materials, GaN nanowires and perovskite nanocrystals.

Suspended etched GaN nano beam image.

Recently we received a grant from the III-V hub in Cardiff to work with Prof. Anthony Bennett on etching suspended GaN waveguide structures, as shown in the image above. A recent publication on this can be found here in AIP Advances from 2020.

We are about to start a new project called "Plasmon-enhanced light emission from hybrid nanowires: towards electrically driven nanowire lasers". This will commence in October 2021 and is a joint project with Dr. Shengfu Yang at the University of Leicester.