Department of
Chemistry

Dr. Pankaj Mandal obtained his PhD in 2015 from the Indian Institute of Science, Bangalore in the field of Microwave Spectroscopy of weakly bound complexes (Advisor: Prof. E. Arunan). He worked as postdoctoral research associate for about 4.5 years (Kansas State University with Prof. Viktor Chikan, and Rowland Institute at Harvard with Dr. Andrew J. Speck) before joining IISER Pune as an Assistant Professor in August 2010.

Research

Terahertz Spectroscopy and Ultrafast Dynamics in Molecules and Materials

Terahertz spectroscopy (1 THz = 10^12 Hz) has emerged as a new spectroscopic technique mostly over the past two decades. This part of the electromagnetic spectra remained elusive for long since its emission and detection relies on ultra-short laser pulses. Thus, only after the invention of ultrafast LASERs it was possible to access the THz gap. Terahertz spectroscopy finds its applications in solid state physics, biology, pharmaceuticals and security screening. More elaborately Terahertz spectroscopy can be used to delve into charge carrier dynamics in semiconductors and nano materials; librational modes of water and other liquids; hydration shell around amino acids, sugars and proteins.

Our group use THz spectroscopy along with other ultrafast time-resolved techniques such as optical Kerr effect (OKE) spectroscopy, and femtosecond transient absorption spectroscopy, to study sub-picosecond dynamics in molecules and materials. Currently, we are interested in understanding the charge carrier and phonon dynamics in photovoltaic and thermoelectric materials. More specifically, we aim to understand the role of carrier-phonon interactions in determining the photovoltaic and thermoelectric efficiencies. We are also interested in understanding the intermolecular interactions in molecular liquids, liquid mixtures, and large bio-molecules in water.

Selected Publications

Maqbool, S. Sheikh, T. Thekkayil, Z. Deswal, S. Boomishankar, R. Nag, A. and Mandal, P. (2021) Third Harmonic Upconversion and Self-Trapped Excitonic Emission in 1D Pyridinium Lead Iodide. The Journal of Physical Chemistry C, DOI: 10.1021/acs.jpcc.1c07639.

Sarkar, S. Banerjee, S. Swarnkar, A. and Mandal, P. (2021) Effect of Capping Ligand Engineering on Transport Properties and Carrier Dynamics in Cubic CsPbI3 Nanocrystal Film. The Journal of Physical Chemistry C, 125, 10539–10548.

Sarkar, S. Ravi, V. K. Banerjee, S. Yettapu, G. R. Markad, G. B. Nag, A. and Mandal, P. (2017) Terahertz Spectroscopic Probe of Hot Electron and Hole Transfer from Colloidal CsPbBr3 Perovskite Nanocrystals. Nano Letters, 17, 5402-5407.

Sarkar, S. Saha, D. Banerjee, S. Mukherjee, A. and Mandal, P. (2017) Broadband Terahertz Dielectric Spectroscopy of Alcohols. Chemical Physics Letters, 678, 65-71.

Yettapu, G. R. Talukdar, D. Sarkar, S. Swarnkar, A. Nag, A. Ghosh, and Mandal, P. (2016) Terahertz Conductivity within Colloidal CsPbBr3 Perovskite Nanocrystals: Remarkably High Carrier Mobilities and Large Diffusion Lengths. Nano Letters, 16, 4838-4848.