Soumya Mahapatra

@home.iitd.ac.in

PhD, Department of Materials Science and Engineering
Indian Institute of Technology Delhi

Soumya Mahapatra


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https://researchid.co/mahapatra

RESEARCH, TEACHING, or OTHER INTERESTS

Multidisciplinary, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Instrumentation
3

Scopus Publications

7

Scholar Citations

1

Scholar h-index

Scopus Publications

  • Impact of Tungsten (W) incorporation on structural, optical and surface wettability properties in RF sputtered TiO2 thin films
    Rajib Saha, Soumya Mahapatra, Robin Sangla, Subhananda Chakrabarti
    Proceedings of SPIE the International Society for Optical Engineering, 2025
    In the current work, TiO<sub>2</sub> thin film (~45nm) is deposited by using RF sputtering technique at 400&deg;C on Si substrate, and W ultra-thin layer is deposited and subsequently annealed at high temperature to diffuse in TiO<sub>2</sub>.The impact of W-incorporation and post-growth annealing on TiO<sub>2</sub> film is analyzed in detail. The change in structural, morphological, and superhydrophilic properties of TiO₂:W film are investigated by using Grazing Incidence X-ray Diffraction (GI-XRD), Atomic Force Microscopy (AFM), Field Emission Gun Scanning Electron Microscopy (FEG-SEM), and static contact angle measurements. XRD reveals the formation of mixed anatase and rutile phases in as deposited TiO<sub>2</sub>, while TiO<sub>2</sub>:W shows the presence of tungsten oxides along with TiO<sub>2</sub> after post-deposition annealing. AFM and FEGSEM results reveal significant increases in surface roughness and granular structures of TiO<sub>2</sub> thin films after W incorporation and annealing. The roughness and thickness of TiO<sub>2</sub> thin film are relatively enhanced from 0.28nm to 1.92nm, and 50nm to 77nm, after W-incorporation and annealing. The static contact angle measurement exhibits the superhydrophilic nature of W-incorporated TiO<sub>2</sub> film with the reduction of contact angle from 83.36&#9900; to 54.70&#9900;. The positive slope indicates an increment in reciprocal of the water contact angle from 9.68E-6<sup>&#9900;-1</sup>/s to 2.50E-5<sup>&#9900;-1</sup>/s, which is attributed to the more hydrophilic nature over time. The results suggest that W incorporation and subsequent annealing significantly enhance the surface roughness and surface wettability parameters of TiO<sub>2</sub> film, which can be a potential candidate for microfluidic on-chip device applications.
  • Investigation of dual-wavelength selective self-powered photo response of ZnO/Si heterojunction with insertion of thin TiO2 layer
    Rajib Saha, Soumya Mahapatra, Avijit Dalal, Anirudhha Mondal, Subhananda Chakrabarti
    Applied Physics A Materials Science and Processing, 2025
  • Post-growth Rapid thermal annealing (RTA): A technological route to achieve high efficient luminescence and reduction of size inhomogeneity in type-II InAs/GaAs(Sb) quantum dots (QDs) heterostructures for opto-electronic applications
    Rajib Saha, Sharanya Chakrabarti, Soumya Mahapatra, Neelu Sharma, Subhananda Chakrabarti
    Proceedings of SPIE the International Society for Optical Engineering, 2024
    In the current work, impact of ex-situ rapid thermal annealing (RTA) on the optical, structural and crystallographic properties of type-II InAs/GaAs(Sb) QDs heterostructures are investigated in detail. The Stranski–Krastanov (SK) QD heterostructure is grown by using solid-source molecular-beam-epitaxy (MBE) technique with 22% of Sb composition in GaAs(Sb) capping layer. The As-grown (ASG) samples are treated with RTA at temperatures of 750 <sub>&deg;</sub>C, 800 <sub>&deg;</sub>C, and 850 &deg;C for 30 s under Ar ambient. Temperature dependent and power dependent photoluminescence (TD-PL and PD-PL) measurements are performed to investigate the impact of the emission properties of type-II heterostructures and such annealing induced changes in QD morphology, optical properties and carrier dynamics are remarkably observed due to alloy intermixing in the QD and capping interface region. The 20 K PL peak reveal a strong correlation with the annealing temperature and a strong blueshift (131 nm). The narrow linewidth from 89 nm (ASG) to 32 nm (850 <sub>&deg;</sub>C) is found due to an increase in the uniformity of QDs and energy states and their evolution with the RTP temperatures are analysed in detail by using deconvoluted PL peaks. Out-of-plane XRD confirms the slight reduction in hydrostatic strain with the increasing RTA temperature due to the decrease in In-content inside InAs QD. Atomic force microscopy (AFM) of uncapped QDs (surface QDs) reveals the formation of highly uniform and dense single QDs family with increasing the annealing temperature to 850 &deg;C, which shows the good agreement with the low temperature PL result. The impact of postgrowth RTP on the InAs/GaAs(Sb) QDs heterostructures on semi-insulating epi-ready GaAs substrates has been studied extensively, and analysis of the optical properties, morphological evolution, and crystallographic change of the QDs as a function of annealing temperature show good agreement, which gives an insight for development of futuristics solar cells devices.

RECENT SCHOLAR PUBLICATIONS

  • Machine learning (ML)-assisted development of 2D green catalysts to support sustainability
    M Dhillon, S Mahapatra, A Basu, SS Pandey, MS Manna, S Bhattacharya, ...
    Materials Horizons 13 (2), 619-640 , 2026
    2026
    Citations: 1
  • Impact of tungsten (W) incorporation on structural, optical, and surface wettability properties in RF sputtered TiO2 thin films
    R Saha, S Mahapatra, R Singla, S Chakrabarti
    Oxide-based Materials and Devices XVI 13367, 183-189 , 2025
    2025
  • Investigation of dual-wavelength selective self-powered photo response of ZnO/Si heterojunction with insertion of thin TiO 2 layer
    R Saha, S Mahapatra, A Dalal, A Mondal, S Chakrabarti
    Applied Physics A 131 (1), 11 , 2025
    2025
    Citations: 6
  • Post-growth rapid thermal annealing (RTA): a technological route to achieve high efficient luminescence and reduction of size inhomogeneity in type-II InAs/GaAs (Sb) quantum …
    R Saha, S Chakrabarti, S Mahapatra, N Sharma, S Chakrabarti
    Infrared Sensors, Devices, and Applications XIV 13145, 121-129 , 2024
    2024

MOST CITED SCHOLAR PUBLICATIONS

  • Investigation of dual-wavelength selective self-powered photo response of ZnO/Si heterojunction with insertion of thin TiO 2 layer
    R Saha, S Mahapatra, A Dalal, A Mondal, S Chakrabarti
    Applied Physics A 131 (1), 11 , 2025
    2025
    Citations: 6
  • Machine learning (ML)-assisted development of 2D green catalysts to support sustainability
    M Dhillon, S Mahapatra, A Basu, SS Pandey, MS Manna, S Bhattacharya, ...
    Materials Horizons 13 (2), 619-640 , 2026
    2026
    Citations: 1
  • Impact of tungsten (W) incorporation on structural, optical, and surface wettability properties in RF sputtered TiO2 thin films
    R Saha, S Mahapatra, R Singla, S Chakrabarti
    Oxide-based Materials and Devices XVI 13367, 183-189 , 2025
    2025
  • Post-growth rapid thermal annealing (RTA): a technological route to achieve high efficient luminescence and reduction of size inhomogeneity in type-II InAs/GaAs (Sb) quantum …
    R Saha, S Chakrabarti, S Mahapatra, N Sharma, S Chakrabarti
    Infrared Sensors, Devices, and Applications XIV 13145, 121-129 , 2024
    2024