D. D. Sarma's Group

As marks a decade of excellence, the editorial team reflects on the key advances made and lays down some of the pressing scientific issues for the next decade in the field of energy research.

A Decade of Excellence Driving the Next Wave of Energy Research CloseNextPreviousDownload Hi-Res ImageDownload to MS-PowerPointCite This:ACS Energy Lett. 2026, # # , # # #, # # #- # # # ADVERTISEMENT InfoMetricsFiguresRef. ACS Energy LettersASAPArticle This publication is free to access through this site. Learn More CiteCitationCitation and abstractCitation and referen...

We are delighted to announce that our former group member, Angshuman Nag, now Professor at IISER Pune has been appointed as the Associate Editor of JACS Au, starting from January 1, 2026. Heartiest congratulations to him.

We are delighted to announce that our former group member Ranjani Viswanatha, currently professor at JNCASR, Bengaluru has been elected as a fellow of the Indian academy of Science (2026). Heartiest congratulations to her.

Rational data analysis matters!

Our recent perspective article introduces a bias-free approach to analyze heat capacity data for thermoelectric materials. Using the Debye-Einstein model, we propose a rational basis that guides the selection of the optimal number of Einstein oscillator terms within a specified temperature range, allowing for robust conclusions. We apply our method to materials with stereochemically active lone pairs (PbBi2S4, PbSnS3, TlBiSe2, and AgPbBiSe3), intrinsic rattler species (TlCuZrSe3 and Bi13S18Br2), soft chemical bonding (CuBiI4), and materials with nanoscale atomic ordering (Cd-doped AgSbTe2), demonstrating its broad applicability. This approach will help streamline future studies and inspire researchers to apply similar rigorous standards in their analyses.

Congratulations to Rohit Rohj, অনুষ্টুপ ইত্যাদি , and Kanishka Biswas

Rational Analyses of Heat Capacity for Thermoelectric Materials Proper data analysis is essential to extracting meaningful insights from raw data. For thermoelectric materials, specific heat measurements provide important clues to thermal properties and are routinely analyzed using the Debye–Einstein model. Conventional treatments often rely on intuition conce...

We are happy to announce that our former group member, Dr. Sanjay Kumar Upadhyay, who is currently working as an Assistant Professor at HNB Garhwal Central University, Srinagar, has been conferred the DAE–SSPS Young Achiever Award at the 69th DAE Solid State Physics Symposium, held at IIT Roorkee from 19–23 December 2025, in recognition of his contributions to condensed matter physics. Heartiest congratulations to him.

Ultrafast Mn2+ sensitization with a massive Stokes shift! Where
does the excess energy go? Check out our recent ACS Energy Letters article where we resolve this long-standing puzzle. It is all about cascading multiphonon relaxations through higher-lying Mn2+ d levels. Congratulations to Poulomi Mukherjee and others.

Energy-Transfer Pathways That Sensitize Mn2+ Emissions Using Mn@CsPbCl3 Nanocrystals as a Generic Platform Photoexcitation of various Mn2+-doped semiconductor nanocrystal hosts gives rise to the celebrated Mn2+ emission. Yet, despite extensive research, the mechanism of sensitizing Mn2+ ions remains little understood. We use Mn2+-doped CsPbCl3 nanocrystals as a platform to probe the de-excitation pathway...

Check out our recent article on the crystal structure and order parameters of trivalent cation-doped vanadium dioxide.
https://doi.org/10.1103/2r7t-rggt
We uncover the true order of the T-M2 phase transition. Congrats to Sayak Mandal and other authors.

Structural phase transitions in lightly doped ${\mathrm{VO}}_{2}$ systems Structural phase transitions in ${\mathrm{VO}}_{2}$ and consequent changes in its physical properties have been cornerstones in the development of condensed matter physics, not only in terms of the spectacular insulator-metal transition in the archetypical monoclinic (M1)-rutile (R) phase transition...

We are pleased to announce that our former group member, Prof. Kalobaran Maiti has been awarded the prestigious Bernard Coqblin Prize in 2025 for his pioneering contributions to correlated electron systems, including high-resolution electron spectroscopy facilities, novel probing methods for complex systems, advancements in quantum materials physics, and significant technology development in India, supporting researchers across institutes and
universities. Heartiest congratulations to him.

We are delighted to announce that our former group member, Prof. Kalobaran Maiti, has been recently appointed as the Director of the Indian Association for the Cultivation of Science, Kolkata. Heartiest congratulations to him.

Our recent work, “New Homologous Series of the 2D Hybrid Lead Iodide System and Its Implications for Photovoltaic Applications,” just published as part of Energy & Fuels special issue “2025 Pioneers in Energy Research: Prashant Kamat”, unravels the structural and optical properties of a new homologous series of 2D hybrid halide perovskite-derived systems. The compounds in this series show exceptionally low exciton binding energies and
high carrier recombination times. We could enhance both the efficiency (24.3% PCE) and stability using this material as a passivator layer on a standard triple-cation perovskite solar
cell. Congrats to Debasmita Pariari and other authors.

New Homologous Series of the 2D Hybrid Lead Iodide System and Its Implications for Photovoltaic Applications Usually, an aliphatic chain or an aromatic ring is used as the organic spacer (A) to form two-dimensional (2D) lead halide compounds with n ≥ 2 in the general formula A2(MA)n−1PbnI3n+1 or A(MA)n−1PbnI3n+1. Departing from this practice to address their limitations, we use a cyclic amine, cycloh...

We are delighted to announce that Angshuman Nag, former group member, now professor at IISER Pune received the Chemical Society of Japan’s Distinguished Lectureship Award at the 105th CSJ Meeting (2025) for his work on photochemistry. Heartiest congratulations to him.

Our collaborative work with Prof. Bhavtosh Bansal’s group at IISER Kolkata, just accepted in PRL, uncovers a new frontier for hybrid halide perovskites! These materials can "remember" their thermal history—like a semiconducting martensite—enabling ultra-precise temperature tracking with 1 K resolution!
Unlike metallic martensites, these semiconductors emit light, allowing an optical read-out of temperature shifts. This breakthrough could revolutionize smart sensors for food, medicine, and beyond!
Huge congrats to Debasmita Pariari and other authors.
Read more: https://link.aps.org/doi/10.1103/PhysRevLett.134.076901

Evidence of Athermal Metastable Phase in a Halide Perovskite: Optically Tracked Thermal-Breach Memory Halide perovskite materials have been extensively studied in the last decade because of their impressive optoelectronic properties. However, their one characteristic that is uncommon for semiconductors is that many undergo thermally induced structural phase transitions. The transition is hysteretic,...