mkumar@nplindia.org

Dr. Mahesh Kumar
Designation:
Senior Scientist &Assistant Professor (AcSIR)
Department:
Advanced Materials and Device Metrology Division
Email address:
mkumar@nplindia.org
Brief Biodata:

Current Research Work:

Dr. Mahesh Kumar is working as Senior Scientist at National Physical Laboratory & Asst Prof. at AcSIR, New Delhi, an NMI of India.

He has worked on the surface physics and Nanostructures and currently working on the ultrafast optoelectronics and Terahertz Photonics. He has a vast experience of Surface Science where he has published more than 50 publications and two books.In the current field of Ultrafast Optoelectronics he has set up a new lab in the year 2013 and since then the lab is producing high quality research work. He is a life member of Materials Research Society of INDIA (MRSI), Indian Science Congress Association (ISCA), Indian Physics Association (IPA) and Indian Laser Association (ILA).

He has established a new facility of Ultrafast Transient Absorption Spectroscopy system with femtosecond laser and a new state of the art lab with the following application areas:

  • Determining the dynamics and kinetics of various materials like Nitride, organics, oxides, graphene etc, so that the high quality materials can be fabricated for efficient device performance.
  • Creation of Terahertz waves with the use of femtosecond laser for the application areas in the R&D and strategic sectors.

Some of the studies being undertaken are as follows:

  • Energy exchange between the electrons and phonons is particularly important to electron transport, and understanding this process will be vital for the realization of devices.
  • Transient absorption spectroscopy is a powerful tool to probe energy relaxation of photo-excited carriers and can be applied extensively to many systems in Graphene, oxides, III-nitrides, III-V, polymers etc.
  • Fabrication of photoconductive Antenna & Generation of Terahertz waves.

Important Publications:

  • P. Kumar, P. D. Sharma, P.E.D S. Rodriguez, M. K.Jharwal, C. SharmaR. Sinha,  Mahesh Kumar  :  Ultrafast carrier dynamics of InxGa1-xN nanostructures grown directly on Si(111)  . Optical Materials, Volume 79 , May 2018, Pages 475–479, DOI: 10.1016/j.optmat.2018.04.003 .

  • Singh, C. Sharma, Mahesh Sharma, R.Kumari, R.Srivastava, S. N. Sharma,  Mahesh Kumar  :  Enhanced Luminescence Efficiency of Wet Chemical Route Synthesized InP-based Quantum Dots by a Novel Method: Probing the Humidity Sensing  Properties. Journal of Luminescence Volume 198, June 2018, Pages 108-116,DOI: DOI: 10.1016/j.jlumin.2018.02.001

  • R. Kumar, N. Gupta, C. Sharma,  Mahesh Kumar:  Synthesis and comparative charge transfer studies in porphyrin-fullerene dyads: Mode of attachment effect  . New Journal of Chemistry 09/2017; 41(22)., DOI: 10.1016/j.carbon.2016.06.034 

  • P. Devi, A. Thakur, S. Chopra, N. Kaur, P.Kumar, N.Singh,  Mahesh Kumar  , S. M.Shivaprasad, M.K. Nayak:  Ultra-sensitive and Selective Sensing of Selenium Using Nitrogen Rich Ligand Interfaced Carbon Quantum Dots  . ACS Applied Materials & Interfaces 03/2017; 9(15)., DOI: 10.1021/acsami.7b00991 .

  • S. Bishnoi, V. Gupta, C. Sharma, D. Haranath,  Mahesh Kumar,  S. Chand:  Luminescent cathode buffer layer for enhanced power conversion efficiency and stability of bulk-heterojunction solar cells  . Organic Electronics 11/2016; 38:193-199., DOI: 10.1016/j.orgel.2016.08.017

  • A.Rana, N. Gupta , A. Lochan, G. D. Sharma, S. Chand,  Mahesh Kumar  , R.K. Singh:  Charge carrier dynamics and surface plasmon interaction in gold nanorod-blended organic solar cell  . Journal of Applied Physics 08/2016; 120(6-6)., DOI: 10.1063/1.4960341

  • S.Bishnoi, V. Gupta, C. Sharma, D. Haranath, S. Naqvi,  Mahesh Kumar  , G.D. Sharma, S. Chand:  Luminescent GdVO4:Sm3+ quantum dots enhance power conversion efficiency of bulk heterojunction polymer solar cells by Förster resonance energy transfer  . Applied Physics Letters 07/2016; 109(2):023902., DOI: 10.1063/1.4958690

  • R. Sharma, H.Lee, V. Gupta, H. Kim,  Mahesh Kumar  , C. Sharma, S.Chand, S.Yoo, D.Gupta:  Photo-physics of PTB7, PCBM and ICBA based ternary solar cells  . Organic Electronics 07/2016; 34:111-117., DOI: 0.1016/j.orgel.2016.04.022

  • R. Kumar, S.Khan, N. Gupta, S.Naqvi, K. Gaurav, C.Sharma,  Mahesh Kumar  , P. Kumar, S. Chand:  Fullerene grafted graphene oxide with effective charge transfer interactions  . Carbon 06/2016; 107., DOI: 10.1016/j.carbon.2016.06.034

  • P. D. Sharma, P.Kumar, C. Sharma,  Mahesh Kumar  , M. K. Nayak:  Structural and Ultrafast Charge Carrier Dynamics of in-situ synthesized rGO/Fe3O4 Nanocomposite  . Materials Letters 05/2016; 181., DOI:
    10.1016/j.matlet.2016.05.186

  • P. Devi, C.Sharma, P. Kumar,  Mahesh Kumar  , M. K. Nayak, M.L. Singla:  Selective Electrochemical Sensing for Arsenite using rGO/Fe3O4 Nanocomposites  . Journal of hazardous materials 03/2016; 322(Pt A)., DOI:   10.1016/j.jhazmat.2016.02.066

  • Mahesh Kumar  , P. Kumar, P. Devi, S M Shivaprasad:  Formation of low-dimensional GaN on trenched Si(5 5 12), probed by STM and XPS  . Materials Research Express 02/2016; 3(3)., DOI: 10.1088/2053-1591/3/3/035010

  • A.Sharma, C. Sharma, B.Bhattacharyya, K.Gambhir,  Mahesh Kumar  , S. Chand, R.Mehrotra, S.Husale:  Plasmon induced ultrafast injection of hot electrons in Au nanoislands grown on CdS film  . Journal of Materials Chemistry C 01/2016; 5(3)., DOI: 10.1039/C6TC04243K

  • P.Dugar,  Mahesh Kumar  , S.Krishna T C, N.Aggarwal, G. Gupta:  Carrier relaxation dynamics in defect states of epitaxial GaN/AlN/Si using ultrafast transient absorption spectroscopy  . RSC Advances 09/2015; 5(102):83969., DOI: 10.1039/C5RA10877B

  • S. Krishna T.C., N. Aggarwal, A.G. Reddy, P. Dugar, M. Mishra, L.Goswami, N.Dilawar,  Mahesh Kumar,  K.K. Maurya, G. Gupta:  Probing the correlation between structure, carrier dynamics and defect states of epitaxial GaN film on (11-20) sapphire grown by rf-molecular beam epitaxy  . RSC Advances 08/2015; 5:73261., DOI: 10.1039/C5RA10099B

  • V. Gupta, V. Bharti,  Mahesh Kumar  , S. Chand, A. J Heeger:  Polymer–Polymer Förster Resonance Energy Transfer Significantly Boosts the Power Conversion Efficiency of Bulk  ‐  Heterojunction Solar Cells  . Advanced Materials 06/2015; 27:4398., DOI: 10.1002/adma.201501275

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