Biswaranjan Nag obtained his DSc (1972) from University of Calcutta specializing in semiconductor physics, solid state and microwave electronics. He served as the Sisir Kumar Mitra Professor of Radio Physics and Electronics, University of Calcutta, Kolkata. He was the Commonwealth Visiting Professor, Bangor, N Wales (1971-72).
Academic and Research Achievements:Nag had developed microwave methods for characterizing semiconductors and made original contributions to the theory of electron transport in elemental and compound semiconductors under various ambient conditions. He developed the theory of energy band structure and electron scattering in superlattices and quantum wells of nonparabolic semiconductors. Biswaranjan formulated for the first time the alloy scattering limited mobility of two-dimensional electron gas and demonstration of its temperature independence. Nag also contributed profusely to the study of electron-phonon interaction and other scattering processes in low dimensional semiconductor structures. He demonstrated the non-parabolic nature of energy dispersion relation for electrons for narrow Quantum Wells. He also refined the theory of interface roughness scattering limited mobility for Quantum Wells with finite barrier height and Well width, in which the wave functions penetrate significantly into the barrier. He also developed empirical relation for the permittivity in a few alloy semiconductors. He devoted all the research effort to the study of electron transport and optical processes in Quantum Nanostructures. Biswaranjan was one amongst the few scientists who felt at ease in both theory and experiment. Apart from his work on hot electron effects and Gunn oscillators, he and his coworkers worked on growth and characterization of a few III-V compounds and heterostructures by Liquid Phase Epitaxy.
Biswaranjan Nag Authored two books: Theory of Electrical Transport in Semiconductors (Pergamon, 1972) and Electron Transport in Compound Semiconductors (Springer – Verlag, 1980) and Physics of Quantum Well Devices (Kluwer). He was a member in the councils of many organizations like Indian Association for the Cultivation of Science, Saha Institute of Nuclear physics, Indian Statistical Institute, and Indian National Academy of Engineering. He was in the senate of IIT, Kharagpur. He served in the boards of Semiconductor Complex Ltd. (Chandigarh), West Bengal Electronics Industries Development Corporation, WEBEL Crystals Ltd, WEBEL Electro-ceramics Ltd. and WEBEL Video Devices Ltd., WEBEL Television Ltd. He worked as expert in various CSIR, DoE and UGC committees and in selection committees of IITs and different Universities. He served in the editorial board of Solid State Electronics (Pergamon Press), Transactions on Microwave Theory & Technique of the IEEE (MTT) and few other national journals.
Awards and Honours:Nag was the recipient of SS Bhatnagar Prize (1975) and INSA Prize for Materials Science (1993). He was the Fellow, Indian Academy of Sciences, Bangalore and Indian National Academy of Engineering.