Research Interests

 Condensed Matter Physics, Thin Film Photovoltaics, Thin Film Coatings for Optoelectronics, Oxide Perovskite Solar Cells, Quantum Nanostructures, Transparent photodetectors, 2D Materials.

 Experience

October 2018-September 2021       INSPIRE Faculty, Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, INDIA.

August 2016-October 2018                Research Associate, Department of Physics,  Indian Institute of Technology, New Delhi, INDIA.

                                                                              “Study of passivation defect states in CZTS thin films and junctions”

August 2010-May 2012                         Project Assistant, Department of Physics, Yogi Vemana University, Kadapa, INDIA.

                                                                              “Development of low cost and environmentally benign absorber material for thin film heterojunction solar cells”

Education

•        Ph.D in Physics, Yogi Vemana University, Kadapa, INDIA,

                      Title: Photovoltaic Materials-Development of Earth Abundant Copper Zinc Tin Sulfide  (CZTS) Thin Film Absorber and Heterojunction Solar Cells

•       M.Sc in Physics, Sri Venkateswara University, Tirupati, INDIA, Specialization: Vacuum and Thin film technology
•       B.Sc (Mathematics, Physics, Computer Science), Sri Krishna Devaraya University,  Anantapur, INDIA.

 Research Activity

 I work on earth abundant inorganic absorbers (Cu-Zn-Sn-S_, Cu-Sn(Sb)-S, Sn-S and perovskites) for photovoltaics, photoelectrochemical, photodetection applications. Thin film synthesis techniques would employ for growth, and characterized by different analytical techniques and theory as well

• Comparative study has been made between sequential sputtering and co-sputtering growth processes.
• Synthesized Cu₂ZnSnS₄ (CZTS) with different composition and stack orders under different temperature and other optimization of deposition parameters to improve the quality of the absorber.
• Incorporated selenium into CZTS in controlled manner to make properties tunable (CZTS_xSe_1-x).
• All sputtered CZTS solar cell with alternative ZnS buffer layer, Mo/CZTS/ZnS/ZnO/ZnO:Al/Al was fabricated and achieved 2.6 % conversion efficiency.
• Fabricated AgInS₂ based solar cell with structure, ITO/AgInS₂/SnS/Ag and demonstrated primary efficiency, 1.3 %
• Cu₂ZnSnS₄ and Cu₂BaSnS₄ films were used as photocathodes in photoelectrochemical cells

 Technical Skills

•  High touch with thin film deposition systems, vacuum pumps and accessories
• Acquired experimental skills in preparation of compound semiconductor films using Pulsed Laser Deposition with in situ RHEED, RF/DC magnetron sputtering, evaporation, and chemical methods
• Experience in working with clean room
• Adequate experimental knowledge on thin film characterization techniques like

                X-ray diffractometer

                 UV-Vis-NIR, Raman spectrophotometer and Ellipsometry

                  Scanning Electron Microscope with X-ray analyzer

                 Atomic Force Microscope and X-ray Photoelectron Spectroscopy

                 Electrical conductivity and Hall effect measurements

                 Electrical probe station for I-V and C-V characterization of Solar cell

 Significant Publications

•       Narayana Thota, Mukesh Kumar, Manoj Vishwakarma and B.R.Mehta

                     Structural, Electronic and Optical properties of Cu₂SnS₃ photo absorber thin films: a combined experimental and computational study,  Thin Solid Films 677(2019) 62-67

•       Narayana Thota, M. Gurubhakar, G.H.Chandra, Y.P.V.Subbaiah, B.R.Mehta, Growth and properties of Cu₂ZnSnS₄ thin films prepared by multiple metallic layer stacks as function of sulfurization time

                      Journal of Materials Science: Materials in Electronics 28 (2017) 11702-11711

•       Narayana Thota, M. Gurubhakar, M.A.Sunil, P. Prathap, Y.P.V.Subbaiah, A.Tiwari Effect of metal layer stacking order on the growth of Cu₂ZnSnS₄ thin films

                      Applied Surface Science 396 (2017) 644-651

•       Narayana Thota, Y.P. Venkata Subbaiah, P. Prathap and G. Hema Chandra, Two step growth mechanism of Cu₂ZnSnS₄ thin films

                      Physica B: Condensed Matter 449 (2014) 255-260

•       Narayana Thota, Y.P.V. Subbaiah, P. Prathap and K.T. Ramakrishna ReddyInfluence of sulfurization temperature on physical properties of Cu₂ZnSnS₄ thin films   

                      Journal of Renewable and Sustainable Energy 5 (2013) 03160

Books

Y.P.V.Subbaiah and Narayana Thota, Development of Earth Abundant CZTS Thin Film Absorber for Solar Cells, LAMBERT Academic Publishers, Germany, ISBN No: 978-620-0-00141-2 (2019)

Training Programs/Schools: 02:   Conferences: 10;    Workshops: 06   and  counting

Honors and Awards

Visiting Faculty,  Department of Electronic Materials Engineering, Research School of Physics, Australian National University, Australia (2022)

INSPIRE Faculty award by Department of Science and Technology, INDIA (2018)

Research Associate Fellowship from Indian Institute of Technology, Delhi, INDIA (2016)

Best Poster award in International Conference on Thin Films, National Physical Laboratory, New Delhi, (2017)

One of the article, Journal of Renewable and Sustainable Energy 5 (2013) 031606 has been in the 5^th among top 10 hottest articles in the field of Photovoltaics (2012)

Teaching

•         PH101 Engineering Physics
•         Involved in curriculum teaching/seminars/discussions to postgraduate and graduate students. Training B.Tech, M.Sc/M.Tech and Ph.D students towards their research activities
•         Subjects taught and interests: Solid State Physics, Statistical mechanics, Semiconductor science and technology, Vacuum and thin film physics, advanced analytical techniques, Solar PV technology  

 Other Activities/Services

 Frequent reviewer to Journal of Alloys and Compounds, Physica B, Thin Solid Films, Materials Science in Semiconductor Processing, Journal of Magnetism and Magnetic Materials, Journal of Physics D: Applied Physics, Nanotechnology