Position: Ph.D. Student

Supervisor: Dr. Rebecca Milot

Research interests: Metal halide perovskites, THz spectroscopy, energy materials, ultrafast photonics.

Funding: EPSRC

Background

I studied my undergrad at Queen Mary University, where I gained a first-class masters' degree in chemistry (2013-2017). In my 3rd-year literature project, I looked at “High-temperature superconductors” with Dr. Isaac Abrahams. In my masters' project, I did a project on “The design and synthesis of materials for Bioelectronics” with Dr. Christian Nielsen. Through these projects, I enjoyed learning about different materials and wanted to do more research in understanding them. With my growing interest in energy materials and renewable energy, I wanted to research metal halide perovskites.

Research Summary

My current research interests are using terahertz spectroscopy to understand the underlying mechanism in Sn and Pb metal halide perovskites that have applications in solar energy. I used optical pump -THz probe (OPTP) techniques to explore the charge carrier dynamics of the material (such as mobility, diffusion length, and lifetime). Besides, I use techniques such as Uv-vis, photoluminescence (including mapping), time-correlated single-photon counting (TCSPC), and transient electron absorption spectroscopy (TEAS) to supplement my work.

Teaching and Demonstrating

This year I have demonstrated for 1st- & 2nd-year electronics labs.

PG-SSLC

I am currently the ethnic minority rep for the physics department.

Publications

Other Interests

During the first and second year of my PhD, I did judo, of which I was a postgrad rep for Judo.

Contact Details

Email: helen.balogun@warwick.ac.uk

Office: Physics 431

 

Above: An image of the Optical-pump terahertz-probe (OPTP) set up that we have in the Warwick centre for ultrafast spectroscopy (WCUS). Link here: https://warwick.ac.uk/fac/sci/wcus/ 

Above: An animation of an optical-pump terahertz probe (OPTP) experiment on a 2D metal halide perovskite sample. In the measurement, the thin film sample is excited by an incoming excitation pulse (also known as the pump) which photoexcites an area of the sample that interacts with the beam (shown in green). After this, an incoming terahertz pulse probes the excited area producing an outgoing terahertz pulse that is detected by photodiodes. This technique is used to measure the conductivity as well as the evolution of charge carriers overtime after photoexcitation. This is done by analysing the difference in the transmission of the terahertz pulse when the pump is 'on' or 'off'.