I obtained BSc Hons degree in Physics from University of Jaffna, Sri Lanka in 2010, and MSc by Research and PhD in Condensed Matter Physics from University of Nottingham in 2012 and 2015, respectively. Following my PhD, I worked as a postdoctoral researcher for 3 years at University of Nottingham and 18 months at University of Manchester. I was appointed as a Lecturer in Physics at Keele University in October 2019.
Research and scholarship
I am interested in studying the fundamental properties and applications of novel 2D materials. My research focuses on the production, characterization and exploitation of 2D materials, especially III-VI van der Waals layered materials. I am collaborating with the University of Nottingham, the University of Manchester and the National Physics Laboratory for various projects.
I have successfully developed a physical vapour deposition method to grow beta-In2Se3 on different substrates (SiO2, mica and graphite) and different In-Se compounds on GaSe crystal (N. Balakrishnan et al., 2016, 2018). Currently I am focussing to develop different band alignment and potential profiles by growing III-VI layers on different layered semiconductors. By combining materials with different band gap energies enable to fabricate different optoelectronic devices, including multi-colour solar cells.
The integration of 2D layered semiconductors with graphene to form heterostructure devices offers new routes to the fabrication of optoelectronic devices such as light emitting diodes (LEDs), fast and ultrasensitive photodetectors, etc. I fabricate van der Waals heterostructure devices to study their optical, electronic and optoelectronic properties (N. Balakrishnan et al., 2014, 2017).
The miniaturization of ferroelectric devices offers prospects for non-volatile memories, low-power electrical switches and emerging technologies beyond existing Si-based integrated circuits. An emerging class of ferroelectrics is based on van der Waals 2D materials with potential for nano-ferroelectrics. I am interested to study the ferroelectric properties of In2Se3 and CuInP2S6 (S. Xie et al., 2021).
Van der Waals 2D materials offer a versatile platform to tailor heat transfer due to their high surface-to-volume ratio and mechanical flexibility. Recently, we studied the nanoscale thermal properties of 2D InSe layers by scanning thermal microscopy (D. Buckley et al., 2021). I am interested to fabricate and characterise thermoelectric devices.
The stacking method of 2D materials has another degree of freedom; the individual layers can be aligned with different angles with respect to each other, which creates a Moiré pattern. The twist angle can be acts as a knob to tune the electronic properties of the stack. Recently, we studied the electronic transport properties of twisted monolayer–bilayer graphene heterostructure. We observed the formation of van Hove singularities that are highly tunable by changing either the twist angle or external electric field and can cause strong correlation effects under optimum conditions (S. Xu et al., 2021). I am interested to explore the other 2D materials twisted heterostructures.
Other research interests
- Energy storage devices (batteries, supercapacitors, hydrogen storage).
- Strain engineering of 2D materials.
Oscillations and Waves
Applied Physics and Emerging Technologies
Full Publications Listshow
Indium Selenides: From the growth to the exploitation. https://meetx.eventsair.com/graphene-week-2021/official-program. Graphene Flagship. full text>
Tunable van Hove singularities and correlated states in twisted monolayer–bilayer graphene. https://meetx.eventsair.com/graphene-week-2021/official-program. Graphene Flagship. full text>
From the growth to the exploitation of two-dimensional InxSey. www.graphene-flagship.eu. full text>
NOVEL APPROACHES TO THE FABRICATION OF NANOSCALE DEVICES.
Laser Writing of the Electronic Activity of Nitrogen and Hydrogen Atoms in Gallium Arsenide. full text>