Debattam Sarkar

Post-doc at Northwestern University, USA

Glory glory Man United

[Mercouri Kanatzidis @MercouriK]

The so-called 329 perovskites, with their A3B2X9 stoichiometry, are attracting broad interest for their lead-free nature, environmental stability, and potential in optoelectronic devices such as solar cells and light emitters....our latest publication in @J_A_C_S: "Ultrafast Carrier Self-Trapping Driven by Strong Exciton–Phonon Coupling in 2D MA3Bi2I6Cl3 Perovskite."
In this work, we explore lead-free 2D hybrid bismuth halide perovskites for optoelectronic applications. Using temperature-dependent photoluminescence and femtosecond transient absorption spectroscopy, we uncover strong exciton-phonon interactions, characterized by giant Huang-Rhys factors, coherent phonon oscillations, and ultrafast carrier self-trapping into small-polaron and self-trapped exciton (STE) states.
Photoexcited carriers rapidly localize, with PL emission primarily from STEs, while free exciton emission is minimal and transient. Comparisons with 0D MA3Bi2I9 and 2D MA3Bi2Br9 highlight how halide composition and dimensionality modulate free excitons versus localization.
Read more: https://t.co/qlPKdyCr38
#Perovskites #LeadFreeMaterials #Optoelectronics #MaterialsScience #Nanotech

[Mercouri Kanatzidis @MercouriK]

In JACS: Deterministic control of the long debated Sn3+ state in AgSnSe2, one of chemistry’s “impossible” oxidation states. Using XPS, Mössbauer, and XAS (backed by DFT), we directly confirm uniform Sn3+ in pristine AgSnSe2. Sb substitution provides a clean chemical knob that drives Sn from +3 to mixed +2/+4 (valence skipping), progressively suppressing superconductivity (Tc ~5 K) and inducing a metal-to-semiconductor transition. A rare system to interrogate how valence reshapes the electronic ground state. DOI: 10.1021/jacs.5c21696

[Debattam Sarkar @DebattamS]

@IyerAbishek Congratulations 🔥

[Mercouri Kanatzidis @MercouriK]

Through Interdisciplinary Work at Northwestern, Advanced Imaging Reveals Hidden Thermoelectric Structure
https://t.co/Py5s3CyaLk

[Debattam Sarkar @DebattamS]

@beingkemist Congratulations debu da

[Debattam Sarkar @DebattamS]

https://t.co/rYgdUI3K3J

[Debattam Sarkar @DebattamS]

Excited to share our 3 articles got accepted last month @J_A_C_S including my work from postdoc @NorthwesternU and PhD @jncasr research. Multislice electron ptychography, relaxor ferroelectricity & paramagnetic spin fluctuation were applied for the first time to thermoelectrics.

[Debattam Sarkar @DebattamS]

https://t.co/mAP5piEBw9

[Kanishka Biswas @kanishkabiswas]

New @J_A_C_S : We reveal relaxor ferroelectricity as the origin of ultralow, glass-like thermal conductivity in crystalline AgPbSbSe₃ -linking polar nanodomain dynamics to phonon scattering @jncasr @ANRFIndia @IndiaDST
https://t.co/PbJaR0cIfo

[Debattam Sarkar @DebattamS]

@PRASADDEBENDRA Congratulations bro

[Kanishka Biswas @kanishkabiswas]

Mo 4d orbital induced rare conduction band convergence and misfit nanostructures boost thermoelectric zT to 1.8 in n-type PbSe. Successful collaboration between @jncasr @iiscbangalore @IITKanpur @IISERPune
Just out in @angew_chem @ANRFIndia @IndiaDST
https://t.co/uMfTVY1hmh

[Kanishka Biswas @kanishkabiswas]

Glassy thermal transport and zT of 2.7 in doped GeTe results from the inhomogeneous ferroelectric instability developed due to local polar distortions near the dopant sites. Just out in Advanced Materials @DebattamS @subarnadas_ @jncasr
https://t.co/G7wUkWUQug

[Kanishka Biswas @kanishkabiswas]

Onsite 4s-3d coupling in Cu drives the local distortion in CuS4 tetrahedra in TlCuS, which resulted in significant anharmonicity and promising thermoelectric performance. Just out in @J_A_C_S
@animesh_bhui @VenkataMatu @jncasr @IndiaDST

https://t.co/90ggFWcZs0

[Debattam Sarkar @DebattamS]

@MoinakDutta0 @RosseinskyGroup Congratulations Moinak da

[Debattam Sarkar @DebattamS]

@PremakumarYanda @WileyGlobal @AdvPortfolio @mpi_CPfS @claudia_felser @cgsbond Congratulations bhaiya

[Kanishka Biswas @kanishkabiswas]

Sub-valent (Bi2)4+ dimer acts as “twin rattler” in complex metal chalco-halide Bi13S18Br2 to tune its electronic and thermal transport properties, which makes it an excellent thermoelectric material. Just out in @J_A_C_S. @jncasr @IndiaDST
https://t.co/2gR4Zv3ig9

[Kanishka Biswas @kanishkabiswas]

Local structural symmetry breaking upon heating, termed as emphanisis, evidenced in Ruddlesden–Popper mixed halide perovskite, Cs2PbI2Cl2. Just appeared in Advanced Materials @AdvSciNews @jncasr @IndiaDST @fermiion
https://t.co/MxwJyKnT5o

[Lakshay Mehta @lakshaymehta08]

@narendramodi Congratulations #NeerajChopra

🥇- South Asian Games
🥇- Asian Championship
🥇- CWG 2018
🥇- Asian Games
🥇- Tokyo Olympics
🥇- Diamond League
🥈- World Championships
🥇- World Championships
🥈- Diamond League
🥇- Asian Games
🥈- Paris Olympics

THE GOAT ATHELETE...!!! 🇮🇳🔥

[Debattam Sarkar @DebattamS]

@femto_apurba Congratulations Apurba Da🤗