Multifunctional Materials Laboratory

Sudakar Chandran's Research Group

Department of Physics, IIT Madras

Dr. Sudakar Chandran


Department of Physics

Indian Institute of Technology Madras 

Chennai, Tamilnadu 600036

(Tel)   91-44-2257-4895  

Email: csudakar at gmail dot com

   csudakar at iitm dot ac dot in;

Defect Engineering of Multifunctional Materials 

Our group’s research is focused on controlling the growth and properties of a wide range of Multifunctional Materials in the form of thin films, nanostructures, complex heterostructures, and characterizing the structural and chemical properties by a wide range of techniques with a special focus on high-resolution transmission electron microscopy (HRTEM) and spectroscopic techniques (XPS, Raman, UV-vis, IR) to understand the defect-structure property correlations. Room temperature semiconducting oxides, multiferroics, nanostructured magnetic materials for biomedical applications, and nanostructured oxides for energy conversion, Li-ion battery, and solar cell applications are the areas of focus in our research group.

Recent Research Output from MFML

Athrey C Dakshinamurthy, C. Sudakar

Influence of the octahedral cation on the evolution of lattice phonons in metal halide double perovskites: Raman spectroscopic investigation of Cs2B'B''Cl6 (B' = Ag1-xNax; B'' = Bi1-xInx)

Physical Review Materials 7, 065401 (2023) 

Sayan Ghosh, C. Sudarshan, C. Sudakar

Influence of lattice vibrations and phonon interactions on the ion transport properties of grain boundary tailored Li1.3Al0.3Ti1.7(PO4)3 solid-state electrolyte ceramics

Journal of Applied Physics 133, 245106 (2023)

Whispering gallery mode micro-lasing in CsPbI3 quantum dots coated on TiO2 microspherical resonating cavities

Subitan Laskar, Athrey C Dakshinamurthy, Sivakumar Chithamallu, C. Sudarshan, and C. Sudakar, Optics Letters, Vol. 48, Issue 10, pp. 2643-2646 (2023)

Athrey C Dakshinamurthy, Mayank Gupta, B R K Nanda*, and C. Sudakar*

Anionic Alloying in Hybrid Halide Cs2AgBiBr6–xClx Double Perovskites: Is it True Alloying or Preferential Occupation of Halide Ions in MX6 Octahedra?

J. Phys. Chem. C 2023, 2023, 127, 3, 1588–1597.

Publication Date:December 30, 2022

The octahedra in alloyed perovskites, Cs2AgBiBr6–xClx, cannot have an equal number of Cl or Br. It can only be made up of preferentially occupied Cl- or Br-rich octahedra. The total energy of the relaxed configuration for Cs2AgBiBr3Cl3 is shown in the black circles. The octahedra represent the complementary pairs of Br6–xClx and BrxCl6–x. Therefore, mixed anionic alloyed perovskites are not truly homogeneous alloys as the anion cannot mix up uniformly in the double perovskite structure. View the article. 

Lithium Vanadium Polyanionic Composite Multielectron Intercalation Cathode Derived from Thermodynamically Unstable Li2VP2O7/Li2VP2O7F

Y. Lokeswararao, M. Viji, Akshay Kumar Budumuru, C. Sudarshan, Sanjiv Kumar, and C. Sudakar

Multielectron intercalation materials are of great interest. In this work Lokesh explored the possibility of making Li2VP2O7F and Lo2VP2O7 and found that these compounds are not stable unlike it was expected to be so. Interestingly, it forms approximately equimolar composition of three phases (see figure). Despite its composite nature we could show reversible two Li ion intercalation reaction in these compositions.

ACS Appl. Energy Mater. (2022) 

Indian Patent by Subhajit Nandy, B R K Nanda and Sudakar Chandran

This is the second patent from our group. Dr. Subhajit Nandy did extensive device studies before we came up with the optimized conditions for all-solid-state photoferroelectric photovoltaic solar cell devices using bismuth ferrite and derived materials. We also have our theory collaborator, Prof. BRK Nanda, for theoretical insights on the role of oxygen vacancies in the optimization of the material's properties.

Indian Patent by Sudakar C, Tapan Kumar Das and P. Ilaiyaraja

This is fourth patent from our group. Dr. Tapan Kumar Das and Dr. P. Ilaiyaraja did extensive optimization on tailoring the blue, green, and green-red emission from inorganic crystalline (Cd, Zn)Se quantum dots-ZnSe amorhous phase composite for white light applications.

Athrey C. Dakshinamurthy and C. Sudakar* 

Photoinduced degradation of thermally stable Cs2AgBiBr6 double perovskites by micro-Raman studies

Mater. Adv., 3 (2022) 5813-5817

Sublattice Distortion Enabled Strong Interplay between Phonon Vibrations, Electron–Phonon Coupling, and Self-Trapped Excitonic Emissions in Cs2Ag1–xNaxBiCl6 Double Perovskites

Athrey C. Dakshinamurthy and C. Sudakar*

J. Phys. Chem. Lett. 2022, 13, 2, 433–439

Publication Date:January 6, 2022

Rohini Sanikop, Nitika Arya, Viswanath Balakrishnan, C. Sudakar

Charge Pumping by Contact Electrification Using Electrostatic Force Microscopy in Bi- and Tri-Layered MoS2 Nanosheets

The Journal of Physical Chemistry, Part C: Energy, Materials, and Catalysis, 125, 22, (2021) 12155–12165

S. Nandy, Pavana S. V. Mocherla, E. Abdelhamid, B. Nadgorny, R. Naik and C. Sudakar 

Coexistence of large negative and positive magnetodielectric response in Bi1-xCaxFe1-yTiyO3-d nanoparticle ceramics

Phys. Rev. B, 103, (2021) 184406.

A.C. Dakshinamurthy, C. Sudakar

Bandgap engineering and sublattice distortion driven bandgap bowing in Cs2Ag1-xNaxBiCl6 double perovskites 

Applied Physics Letters, 118 (2021) 131902. (Editor's Pick)

Also see


Contributing to a better world

JULY 8, 2021

Exploring Double Perovskite Materials for an enlightening and sustainable future 

Science and Technology (The Hindu Businessline)

New double-perovskite: A step closer to holy grail of solar cells

Y. Lokeswararao, M. Viji, Akshay Kumar Budumuru and C. Sudakar  

Enabling high-rate capability by combining sol-gel synthesis and solid-state reaction with PTFE of 4.2 V cathode material LiVPO4F/C 

Materials Today Communications, 27 (2021) 102435 

M. Viji, Akshay Kumar Budumuru, Vidyashree Hebbar, Sanjeev Gautam, Keun Hwa Chae, and C. Sudakar 

Influence of Morphology and Compositional Mixing on Electrochemical Performance of Li-rich Layered Oxides Derived from Nano-platelet Shaped Transition Metal Oxide-hydroxide Precursors 

Energy & Fuels, 35 (5) (2021) 4533-4549