The Dasgupta Research Group @ TIFR

Ultrafast Biophysics and Photomaterials Group

Chemistry with a "Non-local" Perspective!

We are a young and dynamic group interested in deciphering chemical reaction mechanisms of photoinduced reactions specifically at the interface of chemistry and biology with emphasis on the "Energy Problem". Half of the group designs novel ultrafast and structure-sensitive experiments with the aim of understanding collective motions in variety of molecular/biomolecular systems, while the other half is involved in designing novel molecular photomaterials with high fault-tolerence and robustness.



 Experimental Evidence for Solvent-dependent Ternary Phase in Polymer:Fullerene mixtures of BHJ solar cells


We have now provided an elegant demonstration of the hypothesized solvent dependent ternary phase responsible for controlling the nano-morphology of spin-casted films for BHJ solar cells. Nanoscopy through the perspective of exciton diffusion and polaron generation timescales, provide us an unequivocal evidence for nanometric sized seed domains that are solvent dependent during the spin casting process. CONGRATULATIONS to Palas Roy and Ajay Jha! Many more to come! The paper has been accepted in NANOSCALE, an RSC journal. DOI: 10.1039/C5NR06445G


 Dynamic Water Interaction Timescales around Nanocages Deciphered




 We elucidate the timescale of water interaction and dynamics around the metal-organic nanocages. Our work provides the basis for optimizing confined organic photochemistry within supramoleular nanocavities. Our new paper came out in JPCC for this month. Please read the full article here:

Congratulations to Ankita, Ajay and Rahul!! Way to go!


Ultrafast Triplet Generation for Prolycopene in solution


 Abstract Image

We demonstrate the generation of reactive triplets in prolycopene on an ultrafast timescale. This state forms the basis for lycopene formation with high quantum yield of 0.58 if triplet sensitization is carried out through porphyrin sensitizer. Our new paper came out yesterday and is already in Top 20 most downloaded in JPCB for this month. Please read the full article here:

Congrats Vijayalakshmi and Ajay!


Heterogeneity in Polymer-TiO2 interactions


 Abstract Image


A detailed excited state description of the electron transfer process in DPP-based polymer-TiO2  films reveals instrument response function (IRF) limited (<110 fs) charge injection from a minor polymer fraction followed by a picosecond recombination. The major fraction of photoexcited polymers, however, does not show injection indicating pronounced ground state heterogeneity induced due to nonspecific polymer–TiO2 interactions. Our work therefore underscores the importance of gathering molecular-level insight into the competitive pathways of ultrafast charge generation along with probing the chemical heterogeneity at the nanoscale within the polymer–TiO2 films for optimizing photovoltaic device efficiencies. Our paper was in the TOP 20 downloaded papers in JPCB for the month of November-Decemeber 2014. Read our paper at:

  Congrats to Ajay, Vineeth, Hadiya, Satish and Catherine!


Light-induced PCET inside a Nanocage


 Abstract Image


We demonstrate the fastest H-abstraction step using the sequential proton-coupled electron transfer (PCET) event using host-guest CT excitations. Our work lays the basic ground work for envisioning photodriven catalysis in the visible in confined systems and through energy efficient Singlet states. To read this communication that got published in the Journal of the American Chemical Society, follow this llink:

Congrats to Rahul, Ankita and Ajay!


 Normal mode engineering


Our first research paper stressing the importance of low-frequency dynamics in molecular structures got accepted in Journal of Physical Chemistry B and can be found through this link: Our paper

Congrats to Ajay Jha and Debayan Chakraborty for putting together a solid piece of work!!! In future we plan to extend our work to incorporate the "Normal Mode Engineering" concept in many new supramolecular structures.

Our paper is currently the TOP 20 downloaded papers in JPCB for the month of September-October. See the link: Top 20 in JPCB


We currently looking for a highly motivated and talented POSTDOC with background in either Physics, Chemistry or Biology willing to take up challenging problems and participating in a highly interdisciplinary work. Background in optics and electronics will be a plus. If you think you are a good fit, send your CV, 3 letters of recommendation and your proposed area of work to Dr. Jyotishman Dasgupta (

Interested PhD students should come through the regular TIFR entrance examination held annually in December. For further information see:

TIFR Entrance Examination

Positions are available for Junior Research Fellows (JRF) to join our group. These are usually based on departmental vacancy. At this time we are looking for one JRF to join the group.

If you are an undergraduate student with an interest in our program call us or email Dr. Dasgupta.


OUR Contact Address:

Dr. Jyotishman Dasgupta

Room: B-127, B-block 1st Floor

Department of Chemical Sciences,

Tata Institute of Fundamental Research,

 Mumbai, 400005, INDIA

Phone: 91-22-2278-2383