Theoretical: Materials modeling and simulation using Density Functional Theory (DFT), Many-Body Perturbation Theory (MBPT), Molecular Dynamics (MD), and Tight-binding model of 3D bulk and two-dimensional (2D) materials for various novel electronics, and optoelectronics applications.

Experimental: Synthesis and characterization of perovskite materials using various techniques. Photovoltaic device fabrication using RF-DC magnetron-sputtering system, Pulsed laser deposition system, and Spin coating.

1. October 2022- till date: Assistant Professor (Electronics), Hansraj College, University of Delhi, New Delhi.
2. April 2021- October 2022: Young Scientist, Postdoctoral Research, Asia Pacific Center for Theoretical Physics, Pohang, South Korea.
3. December 2013- August 2015: Software Engineer, TATA Consultancy Services, India.

• Digital Electronics and HDL.
• Analog Electronics.
• Programming Fundamentals using Python.
• Printed Circuit Board Designing.

• Mentoring the graduate students via the HRC Mentorship program.
• Mentored and supervised the M.Tech. and M.Sc. students in their six months major, and three months minor projects.

• HRC Journal of Contemporary Science, Managing Editor.
• HRC Research Cell, Department representative.
• Hostal Admissions, Department representative.
• NAAC criteria 5.2, Student Progression.

Ferroelectric oxides and van der Waals materials for photovoltaic applications: Experiment and Theory

1. 2021-2022: Theoretical development of pathways for the fabrication of highly efficient bulk-photovoltaic based next-generation solar cells: Funded by YST, Government of Republic of Korea.

1. R. P. Tiwari “Visible-Light-Activated Enhanced Shift Current Bulk Photovoltaic Effect in Lead-Free Oxychalcogenide Perovskites: Emergence of Fully Inorganic Photovoltaic Materials” J. Phys. Chem. C, vol. 126, no. 25, pp. 10258–10265, 2022.
2. R. P. Tiwari, “Enhanced Shift Current Bulk Photovoltaic Effect in Ferroelectric Rashba Semiconductor α-GeTe: Ab Initio Study from Three- to Two-dimensional van der Waals Layered Structures” Journal of Physics: Condensed Matter, vol. 34, no. 43, pp. 435404-435411, 2022.
3. R. P. Tiwari, B. Birajdar, and R. K. Ghosh, “Intrinsic ferroelectricity and large bulk photovoltaic effect in novel two-dimensional buckled honeycomb-like lattice of NbP: first-principles study” J. Phys. Condens. Matter, vol. 33, pp. 385302-9, 2021.
4. R. P. Tiwari, B. Birajdar, and R. K. Ghosh, “First-principles calculation of shift current bulk photovoltaic effect in two-dimensional α–In2Se3,” Phys. Rev. B, vol. 101, no. 23, pp. 235448–235456, 2020.
5. R. P. Tiwari, S. Z. H. Hashmi, R. Sharma, S. A. Khan, and B. Birajdar, “Synthesis of highly pure and dense 0.9(KNbO3)―0.1(BaNi1/2Nb1/2O3-δ) ceramic with superior magnetic properties,” J. Am. Ceram. Soc., vol. 102, pp. 4659–4669, 2019.
6. R. P. Tiwari, B. Birajdar, and R. K. Ghosh, “Strain engineering of ferroelectric KNbO3 for bulk photovoltaic applications: an insight from density functional theory calculations,” J. Phys. Condens. Matter, vol. 31, pp. 505502–505512, 2019.
7. R. P. Tiwari, J. Shah, R. K. Kotnala, and B. Birajdar, “Electrical microstructure properties of 0.9KNbO3―0.1(BaNi1/2Nb1/2O3−δ) electroceramic,” J. Alloys Compd., vol. 753, pp. 642–645, 2018.
8. R. P. Tiwari, V. Kumar, S. Singh, J. Shah, R. K. Kotnala, and B. Birajdar, “Structural phase transition, impedance spectroscopy and narrow optical band Gap in (1-x)KNbO3―x Ba(Sc1/2Nb1/2)O3,” J. Eur. Ceram. Soc., vol. 38, pp. 1427–1433, 2018.
9. R. P. Tiwari and B. Birajdar, “Ferroelectric, magnetic and optical properties of Ba and Sc co-doped KNbO3,” in AIP Conference Proceedings, 2018, p. 030014.

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• [APCTP Seminar] Ferroelectric oxides and van der Waals materials for photovoltaic applications: Experiment and Theory, 2021.
• [APCTP-IACS-KIAS Joint Conference] Emergent Phenomena in Novel Oxide Materials and Low Dimensional Systems.

• APCTP Winter Workshop 2021: Theoretical Physics BeyondHorizon
• One-month faculty induction program/orientation course.
• Webinar: Transistor Discovery and Microelectronics Evolution.
• Webinar: Horizons of High-Energy Physics