Ruda, Harry E.

Harry E. Ruda | B.Sc. (Imperial College, London), Ph.D. (MIT), FRSC, FIoN, FInstP, FIMMM, FIET, FCAE
Professor, Stanley Meek Chair in Advanced Nanotechnology & Director, Centre for Advanced Nanotechnology

Office: HA 204

Assistant & Business Officer, Centre for Advanced Nanotechnology
Ms Millie Morris
T: 416.978.4556

Research Group: Electronic-Photonic Materials Group

Short bio: Harry Ruda was one of the founders of a Canadian National Centre of Excellence in Photonics. He serves on the National Science and Engineering Council of Canada and on other government panels including those of the DOE, EPA and NSF in the US, and the RAE and EPSRC in the UK. He serves on the international advisory board of the National University of Science and Technology in Moscow. He also has served on the editorial boards of: Journal of Applied Physics, Applied Physics Letters, Journal of Nanoscience and Nanotechnology, Journal of Materials Science: Materials in Electronics, Nanotechnology Research Letters, and is currently Editor in Chief of IET Circuits Devices and Systems.

Professor Ruda has published over 270 publications in international refereed journals (with over 7,200 citations; h=41), has co-authored 4 books and has 14 patents. Professor Ruda’s research interests focus on the fabrication and modeling of quantum functional nanostructures with applications in the fields of nanoelectronics and nanophotonics. Some notable contributions include one of the first theories of carrier transport in selectively doped quantum heterostructures, theories for the non-linear optical response of asymmetric quantum heterostructures, one of the first reports on the growth of semiconductor nanowires.

Honours & Awards

  • Fellow, Canadian Academy of Engineering (CAE)
  • Fellow, Institute of Physics (FInstP, United Kingdom)
  • Fellow, Royal Society of Canada (FRSC)
  •  Fellow, Institute of Nanotechnology
  • Fellow, Institution of Engineering and Technology

Research Interest

Professor Ruda’s research program focus on semiconductor nanostructures for nanoelectronics and nanophotonics. In the former area, they are looking at conventional electron transport as well as quantum transport and spintronics, while in the latter area we are looking at cavity effects, nonlinear optical effects, plasmonics.

Growth of semiconductor nanowire structures

After Wagner and Ellis demonstrated the VLS growth process in 1964 for semiconductor micron-scale whiskers, we were one of the first groups to demonstrate its use for preparing Si nanowires (i.e., diameter ~tens nm) in 1997 [JVST, B15(3),pp.554-557(1997), with 178 SCI citations]. By 1998 Lieber’s first paper was published referencing our work and interest in nanowires grew exponentially from there. Subsequently, we reported on high quality nanowires of GaAs, AlGaAs and recently, ZnSe. Most notable was our demonstration of a short period AlGaAs/GaAs superlattice within a nanowire.

Control over surface states and non-radiative recombination pathways

Our focus is on III-Vs including seminal work on influence of surface structure on surface states [JAP, 75(10), pp.5332-5338(1994)], and surface state/non-radiative recombination control using surface passivation – treatments include chlorine [e.g., APL:67(22),pp.3334-3337(1995);PRB,59(24),pp.766-771(1999); PRL, 85(7), pp.1488-1491(2000)], sulfur [e.g., JAP, 79(7), pp.3758-3762 (1996)], and oxygen [e.g., JAP, 83(11), pp.5880-884(1998)/92(5),pp.2330-2334(2002)]. We continue to collaborate strongly internationally in this area and are well recognized in this field [e.g., Ruda, Science, 283(5402), pp. 646-649(1999)].

Linear/nonlinear optical properties of semiconductor nanostructures

Excitonic effects in Type I/II quantum dots and nanowires, photoconductivity and PL response of nanowires, nonlinear optical response of nanostructures [APL, 65(25), pp.3176-3178(1994); JAP, 75, (1), pp.54-57(1994); PRB, 50(8), pp.5703-5706(1994); IEEE JQE, 31(2), pp.228-231(1995)], polarization sensitive optical properties of nanowires, plasmonic phenomena and luminescence amplification in nanostuctures.

Low dimensional photonic nanostructures

This work covers preparation of photonic crystal (PC) structures – includes inverse opals [Adv. Fun. Mater., 12(1),pp.1-8(2002)] and nanowire array based PCs; studies of properties of PCs and in particular, a proposal for a new type of resonant PC where periodic dielectric constrast media and active gain material with electronic confinement are the same material, and are represented as a nanowire array.

Transport and spin effects in semiconductor nanostructures

We presented one of the first theories of electron transport in a 2D electron gas [Phys. Rev. B30, pp.4571-4582(1984) and Phys. Rev. B29, pp.4818-4820(1984), 314 SCI citations]. This work focused on a 2D electron gas in GaAs and InGaAs, and later was supplemented by the first work on ZnSe at a ZnSTe heterointerface [APL, 49, (1), pp.35-37(1989)]. This latter work also continued to consider the role of different mechanisms as relating to confined electrons [JAP, 59, (4), pp.1220-1231(1986)] and holes [JAP, 59, (10), pp.3516-3526(1989)] in ZnSe, ZnS [JAP, 68(4),pp.1714-1719(1990)] and ZnTe [J. Phys. D, 24, 1158-1162(1991)]. This work progressed to produce one of first systematic investigations on the role of contact phenomena on carrier transport in nanowires and [JAP: 84(11), pp.5867-5872(1998); 86(9), pp.5103-5108(1999); 86(5), pp.2719-2726(1999): Physica, E6(1-4), pp.543-546(2000)]. This led to studies on nanowire carrier transport and on nanowire-based transistor behaviour. The implications of non-equilibrium carrier transport in nanostructures was also considered [Phys. Rev., B55(16), pp.10541-10548(1997); ibid, B6308(8), pp.5203-5207(2001): Nanotechnology, 12, pp.523-528(2001): Physica, A311, pp. 429-442(2002)]. In parallel with this, we initiated studies in spin effects in such low dimensional systems [e.g., JAP, 87(5), pp.2520-2525(2000)], and recently reported on the first observations of high temperature ferromagnetism in Mn-doped ZnO nanowires.

Select Publications

D. Lynall, S.V. Nair, D. Gutstein, A. Shik, I. Savelyev, M. Blumin and H.E. Ruda, “Surface state dynamics dictating transport in InAs nanowires”, Nano Lett., 18, 1387 (2018)

D. Gutstein, D. Lynall, S. V. Nair, I. Savelyev, M. Blumin, D. Ercolani and H. E. Ruda, “Mapping the Coulomb Environment in Interference-Quenched Ballistic Nanowires”,Nano Lett., 18, 124 (2018)

S. Kasap, C. Koughia and H.E. Ruda, “Electrical conduction in metals and semiconductors”, Springer Handbook of Electronic and Photonic Materials, 1-1 (2017)

A.C. Tseng, D. Lynall, I. Savelyev, M. Blumin, S. Wang and H.E. Ruda, “Sensing Responses Based on Transfer Characteristics of InAs Nanowire Field-Effect Transistors”, Sensors, 17, 1640 (2017)

D. Lynall, K. Byrne, A. Shik, S.V. Nair and H.E. Ruda, “Surface properties from transconductance in nanoscale systems”, ACS Nano Lett, 16, 6028 (2016)

C. Fernandes, A. Shik, K. Byrne, D. Lynall, M. Blumin, I. Saveliev and H.E. Ruda, “Axial pn-junctions in nanowires”, Nanotechnology, 26, 085204 (2015)

S.S. Dhayal, L.M. Ramaniah, H.E. Ruda, and S.V. Nair, “Electron states in semiconductor quantum dots”, J. Chem. Phys., 141, 204702 (2014)

R. Cisek, D. Tokarz, N. Hirmiz, A. Saxena, A. Shik, H.E. Ruda, and V. Barzda, “Crystal lattice determination of ZnSe nanowires with polarization-dependent second harmonic generation microscopy”, Nanotechnology, 25, 505703 (2014)

Y. Song, W. Yin, Y.-H. Wang, J.-P. Zhang, Y. Wang, R. Wang, J. Han, W. Wang, S.V. Nair and H.E. Ruda, “Magneto-Plasmons in Periodic Nanoporous Structures”, Nature: Scientific Reports, 4, 4991 (2014)

Y.Song, Y.Wang, B.B.Li, C.Fernandes and H.E.Ruda, “Interface interaction induced ultra-dense nanoparticles assemblies”, Nanoscale, 5, 6779 (2013)

J. Salfi, C. Stewart, S.V. Nair, S. Yongshun, Rusli, C.Y. Chen, C.F. de Souza, and H.E. Ruda, “Antenna-enhanced and polarization sensitive photoresponse in arrays of silicon P–i–N nanowires”, New Journal of Physics, 15, 093029 (2013)

B. Qiao, K. Song, H.E. Ruda, “Characteristics of coherence and information for a Davydov soliton field”, J. Modern Phys., 3, 1907 (2012)

A. Hayat, P. Zareapour, S.Y. Zhao, A. Jain, I. Savelyev, M . Blumin, Z. Xu, A. Yang, G.D. Gu, H.E. Ruda, A.M. Steinberg, and K.S. Burch, “Hybrid high temperature superconductor-semiconductor tunnel diode”, Phys. Rev. X2, 041019 (2012) 239. J. Salfi, S. V. Nair, I. G. Savelyev, and H.E. Ruda, “Evidence for nonlinear screening and enhancement of scattering by a single Coulomb impurity for dielectrically confined electrons in InAs nanowires “, Phys. Rev., B85, 235316(2012)

J. Salfi, N. Paradiso, S. Roddaro, S. Heun, S.V. Nair, I.G. Savelyev, M. Blumin, F. Beltram and H.E. Ruda, “Probing the Gate−Voltage-Dependent Surface Potential of Individual InAs Nanowires Using Random Telegraph Signals”, ACS Nano, 5, 2191 (2011)

R. Cisek, V. Barzda, H.E. Ruda, and A. Shik, “Nonlinear optical properties of semiconductor nanowires”, (Invited) IEEE J. Sel. Topics in Quant. Electron., PP(99), 1(2010)

J. Salfi, I. Savelyev, M. Blumin, S.V. Nair and H.E. Ruda, “Direct observation of single charge detection capability of nanowire field effect transistors”, Nature Nanotechnology, 5, 737 (2010)

C. deSouza, , A. Alizadeh, S. Nair, I. Saveliev, M. Blumin, H.E. Ruda, D. Hays, V.H. Watkins, K.R. Conway and E. Braunstein, ”Mechanism of IR response in nanopatterned InAs/GaAs quantum dot p-i-n photodiodes”, IEEE J. Quant. Electron., 46(5), 832(2010)

T. Xu, N. Zhu, M.Y.C. Xu, L. Wosinski, J.S. Aitchison and H. Ruda, “Pillar array based optical sensor”, Optics Express, 18, 5420(2010)

J. Salfi, S. Roddaro, D. Ercolani, L. Sorba, I. Savelyev, M. Blumin, H.E. Ruda and F. Beltram, “Electronic properties of quantum dot systems realized in semiconductor nanowires”, (Invited Review), Semic. Sci. Technol., 25, 024007(2010)