I started as a postdoctoral researcher in the Organic Electronics group at the Max Planck Institute for Polymer Research in November 2023. I am focusing on studying the interfacial charge recombination processes in metal halide perovskite solar cells.
I completed my Bachelor's degree in Chemistry honours from Seth Anandram Jaipuria College, University of Calcutta, Kolkata, in 2012. I finished my Master's degree with a specialization in Inorganic Chemistry at the University of Calcutta (Rajabazar Science College, Kolkata) in 2014. Then I moved to the Indian Institute of Technology Bombay, Mumbai in 2015 to conduct my Ph.D. research with Prof. Gopalan Rajaraman at the Department of Chemistry. My research interests during my PhD include the investigation of Spin-Hamiltonian parameters in single-molecule magnets containing transition metal and lanthanide ions through ab initio and DFT methodologies. In 2021, I joined at the University of Chicago as a postdoctoral fellow to work with Prof. Laura Gagliardi. There I worked in the area of multi-configuration pair-density functional theory (MC-PDFT) towards its application to magnetic systems and electronic band structure calculation of metal-organic frameworks.
Arup joined the Quantum Materials Dynamics group of Prof. Alessandro Lunghi in October 2024.
Published in the group
2026
Crystalline Dion-Jacobson 2D Layered Sn-Based Perovskites for Field-Effect Transistors
Z. Ling, S. Wang, A. Sarkar, C. Li, L. Gao, R. Zhao, D. Breiby, D. Seferos, E. Sargent, H. Wang, M. Bonn, D. Andrienko, P. Blom, W. Pisula, T. Marszalek
J. Am. Chem. Soc.,
accepted,
2026,
Impact of Ligand-Mediated Inductive Effects on Electrochemical p-Doping of CsPbBr3 Nanocrystals
T. Hettiger, R. Jayabalan, A. Sarkar, J. Hiller, M. Nusshör, D. Andrienko, W. Brütting, M. Scheele
ACS Energy Letters,
11,
567-572,
2026,
[doi]
[abstract]
Lead halide perovskite nanocrystals (NCs) are promising materials for light-emitting diodes (LEDs) due to their wavelength tunability narrow emission line width and high photoluminescence quantum yield. Oftentimes these devices suffer from charge carrier imbalance and reduced charge injection because as-synthesized NCs are covered by long aliphatic ligands. Here we show a ligand exchange to small electron-withdrawing or electron-donating cinnamate ligands. We probe the influences of the ligands’ dipole moment on hole injection by photoluminescence spectroelectrochemistry (PL SEC). We find that hole injection into NCs covered by electron-withdrawing ligands is facilitated and that these NCs exhibit a superior LED performance. Our results emphasize the importance of kinetic hinderance for charge carrier injection into NC films a feature that is more accurately derived by SEC compared to other techniques like photoelectron spectroscopy.
2025
Optimizing Carrier Balance in CsPbBr3 Nanocrystal LEDs: The Role of Alkyl Ligands and Polar Electron Transport Layers
R. Jayabalan, G. K. Hanumantharaju, T. Hettiger, A. Sarkar, F. Zu, A. Ullrich, A. Abfalterer, A. S. Urban, N. Koch, D. Andrienko, M. Scheele, W. Brütting
Advanced Optical Materials,
13,
e01361,
2025,
[doi]
[abstract]
The study of lead halide perovskite nanocrystal based light-emitting diodes (LEDs) has advanced significantly with notable improvements in stability and optical properties. However optimizing charge carrier injection and transport remains a challenge. Efficient electroluminescence requires a balanced transport of both holes and electrons within the emitting material. Here cubic CsPbBr3 nanocrystals passivated with oleylamine and oleic acid are investigated comparing them to ligand-exchanged nanocrystals with didodecyldimethylammonium bromide (DDABr). Nuclear magnetic resonance spectroscopy and transmission electron microscopy confirm successful ligand exchange revealing reduced ligand coverage in DDABr-treated nanocrystals. Photoelectron spectroscopy spectroelectrochemistry and single-carrier devices indicate improved hole injection in DDABr-capped nanocrystals. Density functional theory calculations further reveal the influence of ligand type and coverage on energy levels with oleic acid introducing localized states in native nanocrystals. Additionally incorporation of a polar electron transport layer enhances LED performance by over an order of magnitude in DDABr-capped nanocrystals driven by improved charge balance arising from the spontaneous orientation polarization of the electron transport layer. These findings highlight the critical role of ligand selection passivation degree and charge transport control by the adjacent organic transport layers in optimizing LED efficiency.