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Our Research Focus
We aim to contribute to a sustainable energy future by developing materials that revolutionise energy technologies. Through rigorous science, creative problem‑solving, and a commitment to interdisciplinary collaboration, Bala Materials Lab strives to advance both fundamental understanding and real‑world impact.
Materials Synthesis
We have successfully developed a physical vapor transport 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, we are focusing on low temperature, low-cost synthesis of various advanced materials, such as TMDs, FeSe, ZnS, CdS, etc (L Adams et al. 2024).
Growth of In2Se3 layers on GaSe substrate
Energy Storage
Solid polymer electrolytes (SPEs) are the key to improving electrochemical devices' energy density and safety. In recent years, natural polymers have received tremendous attention due to the latest advances in green technology for a sustainable future. We have fabricated and charaterised supercapacitors contain natural rubber based electrolyte and reduced graphene oxide base electrodes (Kumudu el at. 2024). Now we are elploring other 2D materials based and bio-mass derive electrodes for supercapacitors and battries.
Supercapacitor consists of MG49-NR electrolyte and rGO based electrodes.
Optoelectronics - Energy Conversion
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. We fabricate van der Waals heterostructure devices to study their optical, electronic, and optoelectronic properties (N. Balakrishnan et al., 2014, 2017).
p-GaSe/n-InSe heterojunction
Ferroelectrics - Low Power Electronics
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. We are interested to study the ferroelectric properties of novel 2D materials, such as In2Se3 and CuInP2S6 (S. Xie et al., 2021, A. Day et al., 2022).
Gr/In2Se3/Gr vertical tunneling transistor
Thermoelectric
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). We are interested to fabricate and characterize thermoelectric devices.
Schematic of Scanning thermal microscope
Twistronics
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 act 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). We are interested to explore the other 2D materials based twisted heterostructures.
ρxx(n,D) measured at T = 1.6 K and B = 0 T of samples with twist angles θ ≈ 1.22°, 1.26°, 1.41°,1.47° and 1.6°. The correlated states under D > 0 remain almost at the same D range for all samples, while the correlated states under D < 0 move to larger D when the twist angle increases,
Other ongoing projects
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Strain engineering of 2D materials
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Machine Learning