Pavle Radovanovic

Professor, Chemistry; Canada Research Chair in Spectroscopy of Nanoscale Materials

Research interests: synthesis of new multifunctional nanostructures

Biography

Professor Pavle Radovanovic’s research involves studying the optical, magnetic and electronic interactions in nanosystems and their uses in creating next generation forms of information processing and computer memory. The research is relevant in improving computing performance, speed and energy consumption through new forms of non-volatile computer memory that overcome many limits of existing technology.

As Canada Research Chair in Physical Chemistry and Spectroscopy of Nanoscale Materials, Radovanovic studies how light, magnetic field and electrical current interact in nanometre-scale materials in advanced and next-generation microcomputing. The knowledge gained from this research is a key to designing new forms of information processors and non-volatile Random Access Memory (RAM)—memory that doesn’t disappear with electricity.

One promising new form of RAM stores information with a combination of magnetic field and electricity (magneto-resistance),using much less electrical power in the process. Radovanovic will design nanocrystalline materials that combine the necessary optical, electrical and magnetic properties. By designing and studying these systems, he’ll develop a fundamental understanding of the relationship between the electronic and crystal structure of low-dimensional multifunctional systems and their functional physical properties. His research program will also address the structure-function relationship as a fundamental question in physical-inorganic and materials chemistry. With the RAM and data storage market worth over $100 billion per year, Radovanovic’s research will help ensure Canada is a major player in this field, while advancing the speed and performance of computing, benefiting countless other industries in our increasingly digitized world.

Education

PhD, University of Washington, 2004
MS, Georgetown University, 1999
Diploma of Chemistry, University of Novi Sad, Serbia, 1996

Pavle Radovanovic

Awards and Honours

Year	Awards and Honours
2014	Canadian National Committee for International Union of Pure & Applied Chemistry (CNC-IUPAC) Travel Award

Research

Radovanovic's research program is concerned with synthesis, fundamental physical and chemical properties, and application of designed nanostructured materials that combine tunable optical electrical and magnetic properties.

His group applies a variety of synthetic, crystallographic, microscopic, spectroscopic, magnetic and transport techniques, and perform the measurements of novel nanomaterials at both ensemble and single nanostructure level.

The group's approach is to achieve multifunctionality by using complex nanocyrstalline alloys and compounds that contain multiple selected transition-metal or rare-earth-metal sites. Diluted magnetic semiconductors have already found applications in spin-based electronics (spintronics). This alternative technology relies on the use of electron spins, in addition to charges, for efficient and non-volatile information transmission and possessing.

The rational design and study of complex nanocrystalline alloys and compounds can provide important understanding of the relationship between the crystal and electronic structures of low-dimensional multifunctional systems and their optical, electrical magnetic properties. The group devotes particular attention to the mutual interactions between light, electrical conductivity and magnetization at the nanoscale in the context of novel technological applications. The long-term goal is to understand these materials at the molecular level and to design improved multifunctional nanostructures based on our knowledge of the structure-function relationship.

Hybrid nanostructures can utilize a variety of properties unique to organic and biological molecules to introduce complex functionalities into inorganic nanostructure. Due to their small sizes, high surface areas and tunable molecule-like electronics structures and physical properties, inorganic nanoscale materials potentially allows for increased compatibility with organic and biological systems over bulk materials.

The group is studying electronic coupling between the semiconductor nanostructures and rationally selected organic and biolmolecular adosrbates, which is relevant for nanophotonics and energy conversion technologies. The goal is to understand the properties of nanocyrstalline-surface-bound molecules and their relationship to the electronic coupling processes.

Research Interests

Inorganic multifunctional nanostructures
Inorganic-organic and inorganic-biomolecular hybrid nanostrcutures
Multifunctional nanostructures
Multiferroics, ferromagnetic semiconductors
Spintronics, composite nano- and biomaterials
Biomimetics, spectroscopy, magnetism, electrical transport

Publications

Recent publications include:

Sun, X.; Hegde, M.; Wang, J.; Zhang, Y.; Liao, J.; Radovanovic, P. V.; Cui, B. "Sructural Analysis and Electrochemical Studies of Carbon Coated Li₄Ti₅O₁₂ Particles Used as ANode for Lithium Ion Battery", ECS Transactions,2014, 58, 79-88.
Hosein, I. D.; Hegde, M.; Jones, P. D.; Chirmanov, V.; Radovanovic, P. V. " Evolution of the Faceting Morphology and Aspect Ratio of Galium Oxide Nanowires Grown by Vapor-Solid Deposition", J. Cryst. Growth, 2014, 396, 24-32.
Sun, X.; Hegde, M.; Zhang, Y.; He, M.; Gu, L.; Wang, Y.; Shu, J.; Radovanovic, P. V.; Cui, B. "Structure and Electrochemical Properties of Spinel Li₄Ti₅O₁₂ Nanocomposites as Anode for Lithium-Ion Battery", Int. J. Electrochem. Sci., 2014, 9, 1583-1596.
Wang, T.; Layek, A.; Hosein, I. D.; Chirmanov, V.; Radovanovic, P. V. “Correlation between Native Defects and Dopants in Colloidal Lanthanide-Doped Ga₂O₃ Nanocrystals: A Path to Enhancing Functionality and Controlling Optical Properties”, J. Mater. Chem. C, 2014, 2, 3212-3222. Invited paper.
Hegde, M.; Hosein, I. D.; Sabergharesou, T.; Farvid, S. S.; Radovanovic, P. V. “Introducing and Manipulating Magnetic Dopant Exchange Interactions in Semiconductor Nanowires”, Proc. of SPIE, 2013, 8813, 88132S. Invited paper.
Wang, T.; Chirmanov, V.; Chiu, W. H. M.; Radovanovic P. V. "Generating Tunable White Light by Resonance Energy Transfer in Transparent Dye-Conjugated Metal Oxide Nanocrystals", J. Am. Chem. Soc., 2013, 135, 14520−14523.
Sun, X.; Bai, X.; Wang, Y.; Hegde, M.; Hosein, I. D.; Radovanovic P. V.; Guo, Y. G.; Cui, B. "Comparison of Structural Analysis and Electrochemical Studies of C-Li₄Ti₅O₁₂ and CNT-Li₄Ti₅O₁₂ Nanocomposites Particles Used as Anode for Lithium Ion Battery", MRS Proc., 2013, 1541, mrss13-1541-f09-01.
Radovanovic, P. V. "Defect-Induced Optical and Magnetic Properties of Colloidal Transparent Conducting Oxide Nanocrystals", In Functional Metal Oxides: New Science and Novel Applications, Ogale, S. B.; Venkatesan, T. V.; Blamire, M. (Editors); Wiley-VCH: Weinheim, 2013, Chapter 5, 161-192. Invited book chapter.
Sabergharesou, T.; Wang, T.; Ju, L.; Radovanovic, P. V. "Electronic Structure and Magnetic Properties of sub-3 nm Diameter Mn-Doped SnO₂ Nanocrystals and Nanowires", Appl. Phys. Lett., 2013, 103, 012401.
Farvid, S. S.; Hegde, M.; Radovanovic, P. V. "Influence of the Host Lattice Electronic Structure on Dilute Magnetic Interactions in Polymorphic Cr(III)-Doped In₂O₃ Nanocrystals", Chem. Mater., 2013, 25, 233-244.
Sun, X.; Iqbal, A.; Hosein, I. D.; Yacaman, M. J.; Tang, Z. Y.; Radovanovic, P. V.; Cui, B. "Structure Characterization and Electrochemical Characteristics of Carbon Nanotube-Spinel Li₄Ti₅O₁₂ Nanoparticles", MRS Proc., 2012,1440, mrss12-1440-o09-34.
Farvid, S. S.; Radovanovic, P. V. "Phase Transformation of Colloidal In₂O₃ Nanocrystals Driven by the Interface Nucleation Mechanism: A Kinetic Study", J. Am. Chem. Soc., 2012, 134, 7015-7024.
Hegde, M.; Wang, T.; Miskovic, Z. L.; Radovanovic, P. V. "Origin of size-dependent photoluminescence decay dynamics in colloidal γ-Ga₂O₃ nanocrystals", Appl. Phys. Lett., 2012, 100, 141903.
Ju, L.; Sabergharesou, T.; Stamplecoskie, K. G.; Hegde, M.; Wang, T.; Combe, N. A.; Wu, H.; Radovanovic, P. V. "Interplay between Size, Composition and Phase Transition of Nanocrystalline Cr³⁺-Doped BaTiO₃ as a Path to Multiferroism in Perovskite-Type Oxides", J. Am. Chem Soc., 2012, 134, 1136-1146.
Farvid, S. S.; Hegde, M.; Hosein, I. D.; Radovanovic, P. V. "Electronic structure and magnetism of Mn dopants in GaN nanowires: ensemble vs single nanowire measurements", Appl. Phys. Lett., 2011, 99, 222504.
Wang, T.; Radovanovic, P. V. "Size-Dependent Electron Transfer and Trapping in Strongly Luminescent Colloidal Gallium Oxide Nanocrystals", J. Phys. Chem. C, 2011, 115, 18473-18478.
Hegde, M.; Farvid, S. S.; Hosein, I. D.; Radovanovic, P. V. "Tuning Manganese Dopant Spin Interactions in Single GaN Nanowires at Room Temperature", ACS Nano, 2011, 5, 6365-6373.
Wang, T.; Radovanovic, P. V. "In-situ enhancement of the blue photoluminescence of colloidal Ga₂O₃ nanocrystals by promotion of defect formation in reducing conditions", Chem. Comm., 2011, 47, 7161-7163.
Farvid, S. S.; Wang, T.; Radovanovic, P. V. "Colloidal Gallium Indium Oxide Nanocrystals: A Multifunctional Light Emitting Phosphor Broadly Tunable by Alloy Composition", J. Am. Chem Soc., 2011, 133, 6711-6719.
Wang, T.; Radovanovic, P. V. “Free Electron Concentration in Colloidal Indium Tin Oxide Nanocrystals Determined by Their Size and Structure”, J. Phys. Chem. C, 2011, 115, 406-413.
Farvid, S. S.; Wang, T.; Radovanovic, P. V. “Spectroscopic and Magnetic Properties of Colloidal Transition Metal-Doped Transparent Conducting Oxide Nanocrystals as Building Blocks for Spintronic Material”, Proc. SPIE, 2010, 7760, 77600B.
Wang, T.; Farvid, S. S.; Abulikemu, M.; Radovanovic, P. V. “Size-Tunable Phosphorescence in Colloidal Metastable γ-Ga₂O₃Nanocrystals”, J. Am. Chem Soc., 2010, 132, 9250-9252.
Dave, N.; Pautler, B. G.; Farvid, S. S.; Radovanovic, P. V. “Synthesis and Surface Control of Colloidal Cr3^+- Doped SnO₂Transparent Magnetic Semiconductor Nanocrystals”, Nanotechnology, 2010, 21, 134023.
Farvid, S. S.; Dave, N.; Radovanovic, P. V. “Phase-Controlled Synthesis of Colloidal In2O3 Nanocrystals via Size-Structure Correlation”, Chem. Mater., 2010, 22, 9-11. (Highlighted in Angew. Chem. 2010, 49, 5610-5612)
Farvid, S. S.; Dave, N.; Wang, T.; Radovanovic, P. V. “Dopant-Induced Manipulation of the Growth and Structural Metastability of Colloidal Indium Oxide Nanocrystals”, J. Phys. Chem. C, 2009, 113, 15928-15933. (Highlighted in Angew. Chem. 2010, 49, 5610-5612)
Radovanovic, P. V. “Keeping Track of Dopants”, Nature Nanotech., 2009, 4, 282-283.
Farvid, S. S.; Ju, L.; Worden, M.; Radovanovic, P. V. “Colloidal Chromium-Doped In₂O₃ Nanocrystals as Building Blocks for High-TC Ferromagnetic Transparent Conducting Oxide Structures”, J. Phys. Chem. C, 2008, 112, 17755-17759.
Stamplecoskie, K. G.; Ju, L.; Farvid, S. S.; Radovanovic, P. V. “General Control of Transition-Metal-Doped GaN Nanowire Growth: Toward Understanding the Mechanism of Dopant Incorporation”, Nano Lett., 2008, 8, 2674-2681.
Radovanovic, P. V.; Stamplecoskie, K. G.; Pautler, B. G. “Dopant Ion Concentration Dependence of Growth and Faceting of Manganese-Doped GaN Nanowires”, J. Am. Chem Soc., 2007, 129, 10980-10981.
Radovanovic, P. V.; Barrelet, C. J.; Gradecak, S.; Qian, F.; Lieber, C. M. “General Synthesis of Manganese-Doped II-VI and III-V Semiconductor Nanowires” Nano Lett., 2005, 5, 1407-1411
Archer, P. I.; Radovanovic, P. V.; Heald, S. M.; Gamelin, D. R. “Low-Temperature Activation and Deactivation of High-Curie-Temperature Ferromagnetism in a New Diluted Magnetic Semiconductor: Ni2+-Doped SnO2″ J. Am. Chem. Soc., 2005, 127, 14479-14487.
Radovanovic, P. V.; Gamelin, D. R. “High Temperature Ferromagnetism in Nanocrystalline Ni2+-Doped ZnO” Phys. Rev. Lett., 2003, 91, 157202.
Radovanovic, P. V.; Norberg, N. S.; McNally, K. E.; Gamelin, D. R. “Colloidal Transition-Metal-Doped ZnO Quantum Dots” J. Am. Chem. Soc. 2002, 124, 15192-15193.
Radovanovic, P. V.; Gamelin, D. R. “Magnetic Circular Dichroism Spectroscopy of Co2+:CdS Diluted Magnetic Semiconductor Quantum Dots ” Proc. SPIE-Int. Soc. Opt. Eng., 2002, 4809, 51-61.
Radovanovic, P. V.; Gamelin, D. R. “Isocrystalline Core/Shell Synthesis of High Quality Diluted Magnetic Semiconductor Quantum Dots: Ligand-Field Spectroscopic Studies” Proc. SPIE-Int. Soc. Opt. Eng., 2002, 4807, 223-231.
Radovanovic, P. V.; Gamelin, D. R. “Electronic Absorption Spectroscopy of Cobalt Ions in Diluted Magnetic Semiconductor Quantum Dots: Demonstration of an Isocrystalline Core/Shell Synthetic Method” J. Am. Chem. Soc. 2001, 123, 12207-12214.