Sankar Dhar
Professor and Head,
Department of Physics,
School of Natural Sciences
Email Contact:sankar.dhar@snu.edu.in

Ph.D. in Physics, I.I.T. Kanpur, 1997
M.Sc. in Physics, Jadavpur University, 1989

2012- ……    Professor of Physics, Shiv Nadar University, India  
2007-2012  Senior research scientist, NUSNNI-NanoCore, National university of Singapore
2003-2007  Scientist & program leader, Accelerator center, University  of Maryland, College park, USA
1998-2003  Research scientist, II. Physics Institute, University of Göttingen, Germany 
1997-1998  Post-doctoral fellow, II. Physics Institute, University of Göttingen, Germany

My primary interest is on the functional oxide materials at sub-500 nm thickness range, where fascinating science has manifested over the last decade. New oxide materials with exotic properties and functions for the next generation electronic devices are being explored by growing thin epitaxial 2D/3D films, nano-materials, and hetero-structures using pulsed laser deposition and ion implantation of surfaces. I am currently focused on transparent oxide layers, homo/hetero junction, bandgap engineering, 2D layer-oxide interactions, strain engineering at sharp atomic interfaces, defect induced ferromagnetism and resistive switching. Moreover, I use energetic ion beam for material characterizations and modifications via impurity doping, atomic mixing, alloying, nano-structuring, and solid state catalysis processes.

Invited talk in the conference "Current Trends in Condensed Matter Physics 2015 (CTCMP 2015)" NEISER, Bhubaneswar 2015.
Invited in the 12 International Surface Paints and Coating Symposium at Greater Noida on 7-9 Oct, 2015.
Invited talk in the conference “Emerging Materials: Characterization and Applications (EMCA)”, December 4-6, Kolkata 2014
Invited talk in the National Symposium on Opportunities and Challenges in Condensed Matter and Materials Physics, April 17-19, 2014, Shiv Nadar University.
Invited talk in Int. Conf. “Advanced Nano-Materials, IIT Madras (2012)
Invited talk in India-Singapore Physics Symposium, IIT Delhi (2012)
Invited talk in ICMAT, Singapore (2011)
Invited talk in IUAC -AU symposium “Nano-structuring by ion beam”, Allahabad, India (2011)
Invited talk in int. conf.  “Advanced Nano-materials & Nanotech”, IIT Guwahati, India (2011)
Invited talk in national Ion Beam Workshop, IOP, Bhubaneswar, India (2008)
Invited talk in the International symposium ‘SPIG –21’, Belgrade (2002)
TPSC speaker (1997)   
DST young scientist award (1997)
UGC-CSIR fellowship, India (1991)  GATE fellowship, India (1990)
UGC-CSIR national award for university lecturer (1989)

Probing electron density across Ar+ irradiation-induced self-organized TiO2-x nanochannels for memory application” A. Barman, C.P. Saini, P. Sarkar, A. Roy, B. Satpati, D. Kanjilal, S. K. Ghosh, S. Dhar, A. Kanjilal, Appl. Phys. Lett. 108, 244104 (2016)

Resistive switching in self-organized titanium oxide nano-channels-- A. Barman, C.P. Saini, P. Sarkar, B. Satpati, D. Kabiraj, D. Kanjilal, S. Dhar, A. Kanjilal, J. Appl. Phys. 118, 224903 (2015).

Unexpected observation of spatially separated Kondo scattering and ferromagnetism in Ta alloyed anatase TiO2 thin films”-- T. P. Sarkar, K. Gopinadhan, M. Motapothula, S. Saha, Z. Huang, S. Dhar, A. Patra, W. M. Lu, F. Telesio Pallecchi, Ariando, D. Marré & T. Venkatesan, Nature Scientific Reports 5, 13011 (2015).

Effect of Nb and Ta substitution on donor electron transport and ultrafast carrier dynamics in anatase TiO2 thin-- Kalon Gopinadhan, Brijesh Kumar, Natalie Palina, M. Motapathula, I. Pallecchi, T. P. Sarkar, Y. Zhihua, J. Q. Chen, A. Annadi, A. Rana, Amar Srivastava, D. Marré, Jingsheng Chen, Ariando, S. Dhar, A. Rusydi and T. Venkatesan, J. Mater. Chem. C 3, 6329 (2015).

Anisotropic two dimensional electron gas at the LaAlO3/SrTiO3 (110) interface - A. Annadi, Q. Zhang, X. Renshaw Wang, N. Tuzla, K. Gopinadhan, W.M. Lu, A. Roy Barman, Z.Q. Liu, A. Srivastava, S. Saha, Y.L. Zhao, S.W. Zheng, S. Dhar, E. Olsson, B. Gu, S. Yunoki, S. Maekawa, H. Hilgenkamp, T. Venkatesan, Ariando, Nature Commun. 4, 1838 (1013) (Selected as Science Magazine Editors' Choice: Jelena Stajic, Unexpected Conductivity, Science 14 June 2013: Vol. 340 no. 6138 p. 1267)

Reversible room-temperature ferromagnetism in Nb-doped SrTiO3 single crystals - Z.Q. Liu, W.M. Lu, S.L. Lim, J.B. Yi, M. Yang, S. Dhar, T. Venkatesan, Ariando, Phys. Rev. - Rapid Communication B87, 220405 (2013).

Electronic correlation and strain effects at the interfaces between polar and nonpolar complex oxides- A. Annadi, A. Putra, Z. Q. Liu, X. Wang, K. Gopinadhan, Z. Huang, S. Dhar, T. Venkatesan, and Ariando, Phys. Rev. B 86, 085450 (2012).

Coherently coupled ZnO and VO2 interface studied by photoluminescence and electrical transport across a phase transition- A. Srivistava, T.S. Herng, S. Saha, B. Nina, A. Annadi, N. Naomi, Z.Q. Liu, S. Dhar, Ariando, J. Ding, T. Venkatesan, Appl. Phys. Lett. 100, 241907 (2012).

Reversible ferromagnetism in rutile TiO2 single crystals,  Y.L. Zhao, M. Motapothula, N.L. Yakovlev, S. Dhar, A. Rusydi, Ariando, Q. Wang, T. Venkatesan, Appl. Phys. Lett. 101, (2012) 142105.

Metallic state in La-doped YBa2Cu3Oy thin films with n-type charge carriers- S.W. Zeng, X. Wang, W.M. Lu, Z. Huang, M. Motapothula, Z.Q. Liu, Y.L. Zhao, A. Annadi, S. Dhar, H. Mao, W. Chen, T. Venkatesan, Ariando, Phys. Rev. B 86, 045124 (2012).

Cationic defect induced room temperature spin-polarized ferromagnetism in transparent semiconducting anatase TiO2 thin film via non-magnetic Ta doping - A. Rusydi, S. Dhar, A. Roy Barman1, Ariando, Y. P. Feng, K. Yang, D. Jun, G. Neuber, M. Ruebhausen, H. Hilgenkamp, T. Venkatesan, Phil. Trans. A 370 (2012) 4927.

A New Route to Graphene Processing by Selective Laser Ablation - S. Dhar, A. Roy Barman, G.X. Ni, X. Wang, X. F. Xu, Y. Zheng, S. Tripathy, Ariando, A. Rusydi, K. P. Loh, M. Rubhausen, A. H. Castro Neto, B. Ozyilmaz & T. Venkatesan,  AIP advances 1 (2011) 022109.

Electronic Phase Separation at the LaAlO3/SrTiO3 Interface - Ariando, X. Wang, G. Baskaran, Z.Q. Liu, J. Huijben, J.B. Yi, A. Annadi, A. Roy Barman, A. Rusydi, S. Dhar, Y.P. Feng, J. Ding, H. Hilgenkamp, & T. Venkatesan, Nature Communication 2 (2011) 288.

Resistive Switching Mediated by The Formation of Quasi Conduction Band in A Large Band Gap Insulating Oxide - Z. Q. Liu, D. P. Leusink, W. M. Lu, X. Wang, X. P. Yang, K. Gopinadhan, L. Y. Teng, Y. L. Zhao, A. Annadi, A. Roy Barman, S. Dhar, Y. P. Feng, H. B. Su, G. Xiong, T. Venkatesan, & Ariando, Phys. Rev B 84 (2011) 165106.

Metal-Insulator Transition in SrTiO3-x Thin Film Induced by Frozen-out Carriers- Z.Q. Liu, D.P. Leusink, Y.L. Zhao, X. Wang, X.H. Huang, W.M. Lu, A. Srivastava, A. Annadi, S.W. Zeng, K. Gopinadhan, S. Dhar, T. Venkatesan, & Ariando, Phys. Rev. Lett. 107 (2011) 146802.

Multifunctional Ti1-x TaxO2: Ta Doping or Alloying? - A. Roy Barman, M. Motapothula, A. Annadi, K. Gopinadhan, Y. Zhao, Z. Yong, I. Santoso, Ariando, M. Breese, A. Rusydi, S. Dhar & T. Venkatesan, Appl. Phys. Lett. 98 (2011) 072111.

Stability of Graphene under MeV proton beam Irradiation: Effect of Layer number and Substrate.- S. Mathew, T.K. Chan, D. Zhan, K. Gopinadhan, A. Roy Barman, M.B.H. Breese, S. Dhar, Z.X. Shen, T. Venkatesan & John TL Thong, Carbon 49 (2011) 1720.

Enhanced conductivity of pulsed laser deposited n-InGaZn6O9 films and its rectifying characteristics with p-SiC, p-SiC - R. K. Sahu, R. D. Vispute, S. Dhar, D.C. Kundaliya, S. S. Manoharan, T. Venkatesan, S.-H. Lim, & L.G. Salamanca-Riba, Thin Solid Films 517 (2009) 1829.

Structural and chemical analysis of pulsed laser deposited MgxZn1-xO hexagonal (x = 0.15, 0.28) and cubic (x = 0.85) thin films, S.S. Hullavarad, N.V. Hullavarad , D.E. Pugel, S. Dhar, T. Venkatesan , & R.D. Vispute, Optical Materials 30 (2008) 9931000.

Growth parameter-property phase diagram for pulsed laser deposited transparent oxide conductor anatase Nb:TiO2 - S. X. Zhang, S. Dhar, W. Yu, H. Xu, S. B. Ogale, & T. Venkatesan, Appl. Phys. Lett. 91 (2007) 112113.

Luminescence and epitaxy of ion-implanted a-quartz - K.P. Lieb, P.K. Sahoo1, S. Gasiorek, S. Dhar, & J. Keinonen, Physica B Cond. Mat. 389 (2007) 9.

Light-emitting defects and epitaxy in alkali-ion-implanted alpha quartz - J. Keinonen, S. Gąsiorek, P. K. Sahoo, S. Dhar, & K. P. Lieb,  Appl. Phys. Lett.  88 (2006) 261102.

Growth of highly oriented HfO2 thin films of monoclinic phase on yttrium stabilized ZrO2 and Si substrates by pulsed-laser deposition - S. Dhar, M. S. R. Rao, S. B. Ogale,  D. C. Kundaliya, S. R. Shinde, & T. Venkatesan,  Appl. Phys. Lett. 87 (2005) 241504.

Electrical properties of epitaxial junctions between Nb:SrTiO3 and optimally doped, underdoped and Zn-doped YBa2Cu3O7-δ,  W. Ramadan, S. B. Ogale, S. Dhar, S. R. Shinde, D. C. Kundaliya, M. S. R. Rao, R. L. Greene, & T. Venkatesan,  Phys. Rev. B 72 (2005) 205333.

Cathodoluminescence Vs Dynamical Epitaxy of Ba-doped a-quartz - S. Dhar, S. Gasiorek, P. Sahoo, U. Vetter, V. N. Kulkarni, H. Hofsass, & K. P. Lieb, Appl. Phys. Lett. 85 (2004) 1341.

On the origin of high-temperature ferromagnetism in low temperature processed Mn-Zn-O system - D. C. Kundaliya, S. B. Ogale, S. E. Lofland, S. Dhar, C. J. Metting, S. R. Shinde, K. V. Ramanujachary, & T. Venkatesan, Nature Materials 3 (2004) 709.

Chemically guided epitaxy of Rb-irradiated a-quartz - S. Gasiorek, S. Dhar, K. P. Lieb, T. Sajavaara, & J. Keinonen,  J. Appl. Phys. 95 (2004) 4705.

Ion-beam mixing in Fe/Si bilayers by singly and highly charged ions: evolution of phases, spike mechanism and possible effects of the ion-charge - S. Dhar, P. Schaaf, N. Bibic, E. Hooker, M. Milosavljevic, K. P. Lieb, Appl. Phys A 76 (2003) 773.

Atomic mixing and interface reaction in Ta/Si bi-layers during noble-gas irradiations - S. Dhar, M. Milosavljevic, N. Bibic, & K. P. Lieb, Phys. Rev. B 65 (2002) 024109.

Xenon irradiation of Ni3N/Si bilayers: Surface roughening and interface mixing and reactions - L. Rissanen,  S. Dhar, & K. P. Lieb,  Phys. Rev B, 63 (2001) 155411.

Direct synthesis of b-FeSi2 by ion beam mixing of Fe/Si bilayers - M. Milosavljevic, S. Dhar, P. Schaaf, N. Bibic, M. Han, & K. P. Lieb,  Appl. Phys. A71 (2000) 43.

Oxygen migration during epitaxial regrowth in Cs+ irradiated a-quartz investigated by nuclear reaction analysis - F. Roccaforte, F. Harbsmeier, S. Dhar, & K. P. Lieb Appl. Phys. Lett. 76 (2000) 3709. 

Epitaxial crystallization of a-SiO2 films deposited on single crystalline quartz -  F. Roccaforte, S. Dhar, F. Harbsmeier, & K.P. Lieb,  Appl. Phys. Lett. 75 (1999) 2903.

Ion-beam induced amorphization and dynamic epitaxial recrystallization in a-quartz -  S. Dhar, W. Bolse, & K. -P. Lieb,  J. Appl. Phys. 85 (1999) 3120. 

Charge redistribution among discrete defect levels due to pre-amorphization in Si -  P.K. Giri, S. Dhar, V.N. Kulkarni, & Y.N. Mohapatra,  Phys. Rev. B 57 (1998) 14603.

Atomic transport in Cu/Ge and Co/Ge systems during ion-beam mixing - S. Dhar & V. N.  Kulkarni, Thin solid films 333 (1998) 20.  

Electrically active defects in As-implanted deep buried layers in p-type Si - P. K. Giri,  S. Dhar, V. N. Kulkarni, & Y. N. Mohapatra,  J. Appl. Phys. 81 (1997) 260.

Compound formation under local thermal spikes during ion-beam mixing: Model and its experimental verification - S. Dhar, Y. N. Mohapatra, & V. N. Kulkarni, Phys. Rev. B54 (1996) 5769. 

Room temperature synthesis of copper germanide phase by ion-beam mixing - S. Dhar, T. Som, Y.N. Mohapatra, & V.N. Kulkarni, Appl. Phys. Lett. 67 (1995) 1700.

Cationic Defect mediated ferromagnetism in Ta-TiO2 – S. Dhar et al to be published in “Thin Films and Heterostructures for Oxide Electronics,” Editor  S. B. Ogale, (Springer, USA) 2012 in press.

Epitaxy and cathodoluminance in a-quartz Ge, Ba and Rb ion implantation - K. P. Lieb    P. K. Sahoo, S. Gasiorek, & S. Dhar,  Nucl. Inst. & Meth. 244 (2006) 272.

Wide band gap ZnO and ZnMgO Heterostructures for future optoelectronic devices - R. D. Vispute, S. S. Hullavarad, D. E. Pugel, V. N. Kulkarni. S. Dhar, I. Takeuchi, & T. Venkatesan, “Thin Films and Heterostructures for Oxide Electronics,”  Editor  S. B. Ogale, p 301-330 (Springer, USA) 2005.

Competition between the growth of solid solution and iron silicides layers due to ion beam irradiations in Fe/Si bilayers - S. Dhar, N. Bibic M. Milosavljevic, P. Schaaf, & K. P. Lieb, Physics of Ionized Gas, 2002.

Thin Film analysis via Resonant Nuclear Reaction analysis - K. P. Lieb, E. Carpene, S. Dhar, M. Han, L. Rissanen, P. Schaaf, M. Schwickert, & M. Uhrmacher Application of Nuclear Physics, 2002.

Structuring thin films and surface by ion beam - K. P. Lieb, W. Bolse, S. Dhar,  S. Habenicht, M. Neubauer, F. Roccaforte, & M. Uhrmacher  Physics of Ionized Gas, 1998.

Professor Sankar Dhar has joined Physics department of SNU in 2012. He obtained his Ph.D. degree in Physics from I.I.T. Kanpur in 1997 and master degree in physics from Jadavpur University in 1989. After receiving DST young scientist award in 1997, he joined as a post-doctoral fellow and later (1998-2003) worked as a scientist and group leader of the ion beam based materials research program in II. Physics Institute at the University of Göttingen, Germany. Later in 2003, he joined as a leader of ion beam based materials research program of the Accelerator center at the University of Maryland, College Park, USA. Prior to joining SNU, Prof. Dhar worked in the National university of Singapore (NUS) from 2007 as a senior scientist for building and developing the NUSNNI-NanoCore, an integrated new nano-materials research center. He is enthusiastic about teaching and his general research interests include the growth of functional thin films/nano-materials and manipulating their structural, electronic, magnetic, and optical properties using pulsed laser and ion beam. He has filed several patents and published over 120 articles in referred international journals and books.