Quantum coherence and carrier dynamics in colloidal nanostructures from dots to 1D and 2D materials
Prof W W Langbein
Prof P Borri
Dr E Muljarov
No more applications being accepted
Competition Funded PhD Project (European/UK Students Only)
Colloidal nanostructures such as semiconductor quantum dots are relatively simple to manufacture, widely tuneable in shape and size and can be made of a large range of materials. They are useful as optical biomarkers, wavelength converters on light emitting diodes, for solar energy applications, and quantum information processing. For all these applications, a better understanding of the light-matter interaction properties of these nanostructures is needed.
The proposed project investigates the quantum coherent light-matter interaction regime and associated carrier dynamics of electrons and holes in novel colloidal structures developed to achieve a dephasing time limited solely by the radiative lifetime. A variety of different structures will be investigated towards this goal. These include CdSe/ZnS platelets [Phys. Rev. B 91, 121302(R) (2015)], CdSe/CdS dots [Phys. Rev. Lett. 108, 087401 (2012)], InP/ZnSe dots, and perovskite quantum dots [Nano Lett. (2018) DOI 10.1021/acs.nanolett.8b03027]. These materials will be compared and contrasted with defect states in 1D materials (Carbon nanotubes) and 2D materials (transition metal dichalcogenides such as MoSe2 [Phys. Rev. B 96, 045407 (2017)]).
Notably, blinking and jitter of the optical transitions in all these materials, due to charge fluctuations in the environment, is currently limiting their applicability for quantum optics. The origin of these effects will be determined in this project by using single emitter four-wave mixing and photoluminescence measurements, in order to reduce or eliminate these issues.
You will perform the measurements using, and further developing, our world-leading heterodyne-detected four-wave mixing setup described in our recent publications, as given below. You will develop experimental skills and knowledge in optics & lasers by using femtosecond lasers systems and a complex optical setup. You will develop skills in programming by adapting the software to control the experiment. You will perform data analysis and modelling using the knowledge on the physical processes involved
Feasibility of completion within 3.5 years: The project outline plan is as follows; Month 1-9: literature review, training on HFWM setup and data analysis. Month 10-18: Dephasing and dynamics in Perovskite QDs – size and composition dependence. Publication. Month 19-27: Carbon nanotubes. Publication. Month 28-33: Nanoplatelets & TMDCs (2D). Publication. Month 35-38: thesis writing, submission,viva
Full UK/EU tuition fees plus stipend matching UKRI Minimum.
Full awards are open to UK Nationals and EU students who meet UK residency requirements. To be eligible for the full award, EU Nationals must have been in the UK for at least three years prior to the start of the course including for full-time education.
A small number of awards may also be made available to EU Nationals who do not meet the above residency requirement, provided they have been ordinarily resident in the EU for at least three years before the start of their proposed programme of study
M.A. Becker et al., Nano Lett. (2018) DOI 10.1021/acs.nanolett.8b03027
L. Scarpelli et al., Phys. Rev. B 96, 045407 (2017) DOI 10.1103/PhysRevB.96.045407
A. Naeem et al. Phys. Rev. B 91, 121302(R) (2015) DOI 10.1103/PhysRevB.91.121302
How good is research at Cardiff University in Physics?
FTE Category A staff submitted: 19.50
Research output data provided by the Research Excellence Framework (REF)
Click here to see the results for all UK universities