Research Interests:
- Energy Sustainability and Energy materials
- Magneto – optical effects in ferrofluids: Physics and applications
- Magneto-plasmonics for sensing applications
- Renewable energy with a focus on photovoltaics
- Interaction of light with metallic nanostructures (Nanoplasmonics)
- Pedagogical techniques to teach fundamental undergraduate physics courses
Group Members:
1. Nilofar Naaz (Institute Scholar)
Alumni (Research scholars and undergraduate students):
1. Dr. Srinivasa Vutla Rao (Managing Director, Hemair Systems Pvt. Ltd.)
2. Dr. Hemanth Kumar Narsetti (Assistant Professor, St. Peter's College of Engineering, Hyderabad)
3. Dr. Renuka Hyder Khan (Post-Doctoral Researcher, Carnegie Mellon University, Pittsburg, USA)
4. Dr. Waseem Ahmad Wani
5. Dr. Astha Sethi (Scientist, Intel, USA)
6. Dr. Sruthi V Babu (Scientist, Minnessota, USA)
7. Piyush Rath (Engineer, Byju's, Bangalore)
8. Bharat Ravi Kumar (Engineer, QualComm, USA)
9. Pavani (Ph.D. student, Purdue University)
10. Jasvith Basani (Ph.D. student, University of Maryland, USA)
11. Nikhil Navaratna (Ph.D. student, NTU, Singapore)
12. Anirudh Ramesh (Ph.D. student, North Western University, USA)
13. Manav Shah (Ph.D. student, University of Arizona, USA)
14. Vasudha Varadrajan (Ph. D. student, SUNY, USA)
15. Harikrishnan (Scientist, BARC)
16. Vimarsh Srivsatava (Engineer, ARM, Bangalore)
17. Shahela (Engineer, Hyderabad)
18. Apoorva Agrawal (Engineer, GE, Bangalore)
19. Madhan Thyagarajan
20. Mohit Goel
21. Rishabh Mehra
22. Ashi Sinha
23. Dhyana Teja Reddy
Research Collaborators:
1. Prof. Harihara Venkataraman (Dept. of Physics, BITS-Pilani, Hyderabad Campus)
2. Prof. Sanket Goel (Dept. of Electrical Engineering, BITS-Pilani, Hyderabad Campus)
3. Prof. Balaji Gopalan (Dept. of Chemistry, BITS-Pilani, Hyderabad Campus)
4. Prof. S. P. Regalla (Dept. of Mechanical Engineering, BITS-Pilani, Hyderabad Campus)
5. Prof. Prasant Pattnaik (Dept. of Electrical Engineering, BITS-Pilani, Hyderabad Campus)
6. Prof. Challa V Kumar (Dept. of Chemistry and Molecular and Cell Biology, University of Connecticut, USA)
7. Collaboration with the McSEE consortium at BITS-Pilani, Hyderabad Campus
Patents:
1. US patent No: US8084374B2 “Tuning of photo-absorption materials through use of magnetic fields”, Sophia E. Hayes, Stacy Mui, K. Ramaswamy, December 2011
2. Srinivasa Rao Vutla, Srinivasa Prakash Regalla, K. Ramaswamy, Hemair Systems Private Limited, “Sustainable Microelectromechanical Systems (MEMS) Cleanroom”, Provisional Indian Patent filed, Ref/App.No.: 201941041293/TEMP/E-1/43749/2019-CHE, Dated:11/OCT/2019
3. Waseem Ahmad Wani, K. Ramaswamy, Harihara Venkataraman, German Patent granted, Ref/App No.202022104746.4. October 2022
4. Waseem Ahmad Wani, Harihara Venkataraman, K. Ramaswamy, Indian Patent filed, App No:202241062401, November 2022
Publications from BITS-Pilani
41. Defect induced control on current conduction of Cobalt doped BiFeO3 thin-films, Waseem Ahmad Wani, Harihara Venkataraman, K. Ramaswamy, Journal of Electronic Materials (accepted)
40. Connecting electrical current conduction and Urbach energy in doped BiFeO3 thin-films, Waseem Ahmad Wani, Harihara Venkataraman, K. Ramaswamy, Materials Chemistry and Physics, 298, 127468 (2023)
39. Structural and optical investigations in undoped and rare-earth doped zinc oxide nanoparticles for photon upconversion based applications, Waseem Ahmad Wani, Harihara Venkataraman, , K. Ramaswamy, Materials Today Proceedings, 72, 154-161 (2023)
38. Role of Molybdenum Doping in Reducing Leakage Current Density of BiFeO3 based Thin Film Devices, Waseem Ahmad Wani, Harihara Venkataraman, K. Ramaswamy, Ferroelectrics, 598 (2022)
37. Sensing Techniques and Interrogation Methods in Optical MEMS Accelerometers: A Review Balasubramanian Malayappan , U. Poorna Lakshmi, B. V. V. S. N. Prabhakar Rao, K. Ramaswamy, and Prasant Kumar Pattnaik, IEEE Sensors, 22, 6232, (2022).
36. What ails the photovoltaic performance in single-layered unpoled BFO? – The role of oxygen annealing in improving the photovoltaic efficiency, Waseem Ahmad Wani, H. Renuka, Souvik Kundu, Sanket Goel, Harihara Venkataraman, K. Ramaswamy, Solar Energy 236, 822, (2022).
35. Influence of Water Turbidity Upon the Solar Radiation and Photovoltaic Response of Amorphous Silicon Based Underwater Solar Cells, Nilofar Naaz, Prasanth K Enangati, Waseem Ahmad Wani, Sanket Goel, K. Ramaswamy, Energy Proceedings, 23, 571, (2021).
34. Significantly reduced leakage current density in Mn-doped BiFeO3 thin films deposited using spin coating technique, Waseem Ahmad Wani, Nilofar Naaz, Souvik Kundu, Harihara Venkataraman, K. Ramaswamy, J. Phys. - Conf. Series 2070, 12088, (2021).
33. A Study on the effect of Cr doping on the Structural, Optical and Photovoltaic Properties of BFO based Heterostructures, H. Renuka, B. Harihara Venkataraman, K. Ramaswamy, Souvik Kundu, and Sanket G, IEEE Explore, 1182 (2021).
32. Enhanced photovoltaic response in ferroelectric Ti-doped BFO heterojunction through interface engineering for building integrated applications of solar energy, H. Renuka, A. Garudapalli, James Raju, B. Harihara Venkataraman, K. Ramaswamy, S. Kundu, S. Goel, Solar Energy, 225,863 (2021).
31. Submerged solar energy harvesting using ferroelectric Ti-doped BFO based heterojunction solar cells, H. Renuka, P. K. Enaganti, B. Harihara Venkataraman, K. Ramaswamy, S. Kundu, S. Goel, International Journal of Energy Research, 45, 20400 (2021).
30. Extensive enhancement in charge collection efficiency of ferroelectric Cr-doped BFO based solar cells by using TiO2 nanotube arrays, H. Renuka, S. Sharma, B. Harihara Venkataraman, K. Ramaswamy, K. N. Chappanda, S. Kundu, S. Goel, IEEE J. of Photovoltaics, 11, 1278 (2021).
29. Tunable bandgap in Cobalt doped in bismuth ferrite nanoceramics: The role of annealing temperature, Waseem Ahmad Wani, Souvik Kundu, K. Ramaswamy, Harihara Venkataraman, Materials Science and Engineering B, 271, 115299 (2021).
28. Enhancing functionality of free space and guided-wave optical MEMS devices by integration with photonic circuits, M. Balasubramanium, P. U. Lakshmi, B. V. V. S. N. Prabhakar Rao, K. Ramaswamy, P. K. Pattnaik, Optik, 243, 166955 (2021).
27. Faraday rotation in ligand capped Fe3O4 nanoparticles - Experimental investigations for single scattering model, Hemanth Kumar Narsetti, Waseem Ahmad Wani, Nikhil Navaratna, K. Ramaswamy, Dinabandhu Patra, Balaji Gopalan. Journal of Magnetism and Magnetic Materials, (2021), 528, 15, 167779.
26. Influence of transition metal ion doping on structural and dielectric properties of sol - gel synthesized bismuth ferrite nanoceramics, Waseem Ahmad, Souvik Kundu, K. Ramaswamy and B. HariharaVenkataraman, IEEE explore (2020).
25. Influence of thermal treatment on the physical properties of bismuth ferrite nanoceramics for promising multifarious device applications, Waseem Ahmad, Souvik Kundu, K. Ramaswamy and B. Harihara Venkataraman, , AIP conference proceedings, 2269, 030013 (2020)
24. Optimizing Phase Formation of BiFeO3 and Mn-doped BiFeO3 nanoceramics via thermal treatment using Citrate Precursor Method:, Waseem Ahmad Wani, Souvik Kundu, K. Ramaswamy and Hariharavenkataraman, Applied Sciences (Springer Nature), 2, 1969 (2020).
23. Structural, morphological, optical and dielectric investigations in Cobalt doped Bismuth Ferrite nanoceramics prepared using the sol-gel citrate precursor method, Waseem Ahmad Wani, Souvik Kundu, K. Ramaswamy, and B. Harihara Venkataraman Journal of Alloys and Compounds, 846, 156334, (2020).
22. Investigation of the combined effects of electron transport and hole transport layers and suppressing recombination through surface engineering to realize efficient chromium doped BiFeO3 ferroelectric photovoltaic devices, Renuka H, P. Joshna, B. H. Venkataraman, K. Ramaswamy and Kundu. S., Solar Energy, 207, 767-776 (2020).
21. Plasmonic gold nanorods mediated p-BFCrO/n-rGO heterojunction in realizing efficient ferroelectric photovoltaic devices, Renuka H, P. Joshna, W. A. Wani, B. H. Venkataraman, K. Ramaswamy and Kundu. S., Materials Science in Semiconductor Processing, 109, 104937 (2020).
20. Life cycle assessment of cleanroom for micro-electro-mechanical systems fabrication with insights on sustainability, Srinivasa Rao Vutla, Srinivasa Prakash Regalla, K. Ramaswamy, Elsevier, Journal of Cleaner Production, 282, 124520 (2020).
19. A Laminar Fluid Flow Model for Study of Ventilation Systems in Microelectromechanical Systems (MEMS) Clean Room, Srinivasa Rao Vutla, Srinivasa Prakash Regalla, K. Ramaswamy, IOP J. Phys.: Conf. Ser. 1276, 12057 (2019).
18. Optimization Strategy aided by an interplay between plasmonic material and nanoarray geometry for light trapping applications on thin-film photovoltaics, Venkataramanababu, S., Shah, M., Vasudevan, H. and K. Ramaswamy, Plasmonics, 11, 1467-1473, (2016).
17. Optical Absorption of a Silicon Substrate Dressed with Metallic Nanostructures: A Computational Study Harikrishnan, Vimarsh Srivastava, Astha Sethi and K. Ramaswamy, Advanced Science Letters, 20 (7/8/9), 1325-1330, (2014).
16. Effect of Particles and Contaminants on the Static Response of a Rectangular MEMS Diaphragm Due to Adverse Clean Room Environment Simulation Studies, Srinivasa Rao Vutla, Prasant Kumar Patnaik, K. Ramaswamy, Srinivasa Prakash Regalla, M. B. Srinivas, IEEE Explore (2013)
Publications from Post-Doc and Ph.D.
15. Mui, S; Crooker, S; Pan, X; Sanders, G. D; Stanton, C. J.; and Hayes, S. E., Phys. Rev. B, 82, 085209, (2010). Optically Pumped NMR: Revealing spin-dependent Landau level transitions in GaAs, K. Ramaswamy
14. Manifestation of Landau level effects in optically-pumped NMR of semi-insulating GaAs, Mui, S; K. Ramaswamy; Stanton, C. J.; Crooker, S and Hayes, S. E, Phys. Chem. Chem. Phys, 32, 7031, (2009).
13. Physical Insights from a Penetration Depth Model of Optically-pumped NMR. Mui, S; K. Ramaswamy; Hayes, S .E, J. Chem. Phys, 128, 052303, (2008).
12. Optically-pumped NMR of semiconductors, Hayes, S .E; Mui, S; K. Ramaswamy,. J. Chem. Phys, 128, 052203, (2008), (Invited Review).
11. Effects of optical absorption on 71Ga optically polarized NMR in semi-insulating GaAs: measurements and simulations, Mui, S; K. Ramaswamy; Hayes, S .E Phys. Rev. B, 75(19), 195207, (2007).
10. Determination of 77Se-77Se and 77Se-13C J-Coupling Parameters for the Clusters Re5OsSe8(CN)6 3− and Re4Os2Se8(CN)62−, K. Ramaswamy ; Tulsky, E; Long, J. R; Kao, J; Hayes, S .E, Inorganic Chemistry, 46, 1177-1186, (2007).
9. Light-induced 69Ga hyperfine shifts in semi-insulating GaAs observed by optically polarized NMR, K. Ramaswamy, Mui, S, Hayes, S .E., Phys. Rev. B, 74(15), 153201, (2006).
8. Cd(II)-ethylenediamine mono- and bimetallic complexes- Synthesis and characterization by 113Cd NMR spectroscopy and single crystal X-ray diffraction, Ma, G, Fischer, A, Nieuwendaal, R; K. Ramaswamy; Hayes, S. E., Inorganica Chimica Acta, 358, 3165-3173, (2005).
7. Enhancement of the central transition signal in static and magic angle spinning NMR of quadrupolar nuclei by frequency swept fast amplitude modulated pulses, Br¨auniger, T; K. Ramaswamy; Madhu, P .K, Chem. Phys. Lett, 383(3-4), 403-410, (2004).
6. Rare-earth ion assisted nuclear spin-lattice relaxation in Nd3+ doped binary sodium borate glasses -11B NMR study., Mukhopadhyay, S, Ramesh, K .P, K. Ramaswamy, Ramakrishna, J, Phys. Rev. B, 70(22), 224202, (2004).
5. Dynamics and ordering in the columnar mesophases of octa-alkyloxy orthocyclophane- a Carbon-13 NMR investigation, K. Ramaswamy; Sen, T; Poupko, R; Luz, Z; Zimmerman, H, J. Phys. Chem. B, 107(47), 13033-13043, (2003).
4. Anomalous Larmor frequency dependence of proton spin-lattice relaxation time (T1) in the ferroelectric glycine phosphite, K. Ramaswamy; Ramesh, K .P; Ramanuja, M .N; Ramakrishna, J, phys. stat. sol.(b), 225(1), 157-162, (2001).
3. A Versatile and User Friendly Digital Pulse Generator for NMR and NQR experiment, K. Ramaswamy, Ramanuja, M .N; Ramesh, K .P; Ramakrishna, J, NSI, (1995), 19, Dharwad, India.
2. 69Ga Knight shift in semi-insulating GaAs observed by optically polarized NMR, K. Ramaswamy; Mui, S; Hayes, S. E., Bull. Amer. Phys. Soc, 51(2), 1331, (2006).
1. Study of Temperature Dependence of proton T1 in TMAH2PO4, K. Ramaswamy, Ramanuja, M .N, Ramesh, K .P, Ramakrishna, J,. Proceedings of the DAE Solid State Physics Symposium, 40C, 431, (1997).
Conference Proceedings (selected from BITS-Pilani):
1. B. Siva Prasad, Mathews M. John, Atul Goverdhan, K. Ramaswamy and P. Sankar Ganesh, Rapid assessment of persistent organic pollutant, Sulfamethoxazole using surface plasmon resonance based biosensors, 2012, Kottayam, India, National Conference on Conservation and Management of Wetland Ecosystems LAKE2012
2. Srinivasa Rao Vutla, Prasant Kumar Patnaik, K. Ramaswamy, Srinivasa Prakash Regalla, M. B. Srinivas, Effect of Particles and Contaminants on the Static Response of a Rectangular MEMS Diaphragm Due to Adverse Clean Room Environment Simulation Studies, December 2013, Proceedings of IEEE Conference, Prime Asia (available in IEEE explore)
3. Srinivasa Prakash Regalla, Pavan Kumar Gurrala, Sridhar Idapalapati and K. Ramaswamy Strength and Accuracy of FDM Parts and Their Implication on Some New Application Areas of Additive Manufacturing, Pro-AM2014, 2014, Singapore.
4. N. Srinivasa Rao, Avinash Panda, Hemanth Narsetti, Balaji Gopalan, Krishnan Rangan and K. Ramaswamy, Investigations of Faraday Rotation in Fe3O4 and core-shell Fe3O4@Au nanoparticles, National Conference on Advanced Materials for Defense and Aerospace Applications, AMDA2014, 2014, Hyderabad, India.
5. V. Sruthi, Manav Shah, Apoorva Agarwal, Anirudh Ramesh, Shahela, Devesh, Harikrishnan and K. Ramaswamy, Light Trapping in Thin Silicon Substrate: Exciting Insights from Aluminum versus Gold Nanoplasmonics Simulations, SPP7, June 2015, Jerusalem, Israel.
6. Sruthi Venkataramanababu, Manav Shah, K. Ramaswamy 'Photovoltaic current enhancement in thin-film Silicon substrate using random Aluminum nanosphere configurations', MECS 2016, Pondicherry, India
7. Sruthi Venkataramanababu, K. Ramaswamy, 'Spectral Photocurrent estimation in thin-film Silicon substrate using random Aluminum nanosphere configurations', Think Nano 2016, Bangalore, India – Best Poster Award
8. Manav Shah, K. Ramaswamy, 'Tuning and Enhancement of Faraday rotation in metal coated Fe3O4 nanoparticles', Think Nano 2016, Bangalore, India
9. Piyush Rath, Rishab Mehra, Vasudha Varadarajan, Mohit Goyal, Siddharth Dharm and K. Ramaswamy, ‘Temperature control of optical transmission of light through plasmonic nano-hole arrays in Gallium and Eutectic Ga – In alloy’, SPP8, May 2017, Taipei, Taiwan.
10. Vasudha Varadarajan, Piyush Rath, Siddharth Dharm, Rishab Mehra, Mohit Goyal and K. Ramaswamy, ‘Computational analysis of extraordinary transmission of light through plasmonic nanohole arrays in bimetallic systems’, SPP8, May 2017, Taipei, Taiwan
Completed Research Projects
1. Project Title: "Investigation of magneto-optical effects in composite magneto-plasmonic nanostructures for sensing applications"
Funding Agency: DST-SERB (EMR)
Funding Period: 2013 - 2016
Funding amount: Rs. 32.7 Lakhs
Role: PI
2. Project Title: "Investigations of the effects of photon up-conversion materials on the electrical performance of ferroelectric semiconductor heterojunction photovoltaic devices"
Funding Agency: DST-SERB (EMR)
Funding Period: 2018 - 2021
Funding amount: Rs. 35.6 Lakhs
Role: Co-PI for the first 2.5 years and 6 months as PI
3. Project Title: "Clean room for MEMS fabrication"
Funding Agencies: Hemair Systems Pvt. Ltd., DST-TBI, BITS-Pilani
Funding Period: 2013 - 2017
Funding Amount: ~ Rs. 250 Lakhs
Role: Co-PI