University of Toronto | Faculty of Applied Science & Engineering
Department of Materials Science & Engineering
Zheng-Hong Lu | Professor
BSc (China), PhD (École Polytechnique)
Canada Research Chair in Organic Optoelectronics, Tier I
Director, Toronto Microanalysis Centre (TMC)
Office: WB 141
T: 416.978.1472
E: zhenghong.lu@utoronto.ca
Research Group:
Organic Optoelectronics Research Group
Other websites:
http://www.ecf.utoronto.ca/~luzheng/
Awards
Premier's Research Excellence Award (Ontario), 2000
Professional Memberships
Materials Research Society (MRS)
Society of Photo-Optical Instrumentation Engineers (SPIE)
Society for Information Display (SID)
Research Areas
Development of next generation organic light-emtting diodes (OLED's) and solar cells.
Recent Publications
Light ray, in particular Infrared (IR) ray, detecting and imaging have broad applications ranging from fiber optical communication, planetary and biomedical system monitoring. Traditional IR imaging systems use narrow bandgap semiconductors such as ternary HgCdTe compounds and require liquid nitrogen cooling. The system is typically very expensive and cumbersome to operate. Recently, Lu and his collaborators have discovered a new method of IR detecting and imaging by direct integration of a semiconductor detector with an organic light-emitting diodes (OLED). This novel type of imaging chip uses optical IR-to-visible upconverting technology and requires no cooling. This type of imaging chip is compact and has tremendous market potential for several sectors.
D. Ban, Z.H. Lu, and H.C. Liu, “Inorganic/Organic Hybrid Optical Converter with an Embedded Mirror”, US patent pending.
J. Chen, D. Ban, X.D. Feng, Z.H. Lu, S. Fathololoumi, A.J. SpringThorpe, and H. C. Liu, “Enhanced Efficiency in Near-Infrared Inorganic/ Organic Hybrid Optical Upconverter with an Embedded Mirror”, J. Appl. Phys. 103, 103112 (2008).
D. Ban, S. Han, Z.H. Lu, T. Oogarah, A.J. SpringThorpe, and H.C. Liu, “Organic-Inorganic Hybrid Optical Upconverter”, IEEE Transaction on Electron Devices 54, 1645 (2007).
D. Ban. S. Han, Z.H. Lu, T. Oogarah, A.J. SpringThorpe, and H.C. Liu, “Near-infrared to Visible Light Optical Upconversion by Direct Tandem Integration of Organic Light-emitting Diode and Inorganic Photodetector”, Appl. Phys. Lett. 90, 093108 (2007).
Lu group has invented a method of making Ohmic cathode using C60 for OLED application. This new cathode enable OLED to operate at much lower driving voltage with much longer lifetime. This technology has been licensed to Norel Optronics, a Toronto-based Canadian private company.
Z.H. Lu and X. Feng, “Light-emitting Device with Fullerene Layer”. The United States of America (Serial No. 10/811,153); Singapore Patent 117,680 (issued 2008).
X.D. Feng, C.J. Huang, V. Lui, R.S. Khangura, and Z.H. Lu, “An Ohmic Cathode for Low Voltage Organic Light-Emitting Diodes”, Appl. Phy. Lett. 86, 143511 (2005).
Y.Q. Zhao, C.J. Huang, T. Ogundimu, and Z.H. Lu, “Transparent conducting C60:LiF nano-composite thin-films for organic light-emitting diodes”, Appl. Phys. Lett. 91, 103109 (2007).
M. G. Helander, Z. B. Wang and Z. H. Lu, “Contact formation at the C60/alkali-metal fluoride/Al interface”, Appl. Phys. Lett. 93, 083309 (2008).
Fullerene containing hole injection structure has been invented as an universal structure which enables the use of simple metals as anode for OLED application. This technology has been licensed to a Norel Optronics.
Z.H. Lu, S.J. Han, and Y.Y. Yuan, “ORGANIC LIGHT-EMITTING DEVICES WITH MULTIPLE HOLE INJECTION LAYERS CONTAINING FULLERENE”, US Patent 7,358,538 (issued 2008).
S. Han, Y. Yuan, and Z.H. Lu, “Highly Efficient Organic Light-emitting Diodes with Metal/Fullerene Anode”, J. Appl. Phys. 100, 074504 (2006).
Y.Y. Yuan, S. Han, D. Grozea, and Z.H. Lu, “Fullerene-organic Nanocomposite: A flexible Materials Platform for Organic Light-Emitting Diodes”, Appl. Phys. Lett. 88, 093503 (2006).
The novelty of this work is to lay down semitransparent cathode for top emission OLED using thermal evaporation method, which provides a new process pathway for TOLED manufacturing. This technology has been transferred to Luxell Technology, a Toronto-based Canadian public company.
S. Han, X. Feng, Z.H. Lu, R. Wood, and D. Johnson, “Transparent-cathode for Top-emission Organic Light-emitting Diodes”, Canadian Patent: CA2412379; US10/535893.
S. Han, X. Feng, Z.H. Lu, R. Wood, and D. Johnson, “Transparent-cathode for Top-emission Organic Light-emitting Diodes”, Appl. Phys. Lett. 82, 2715 (2003).
Lu group has established a theoretical framework for charge injection and transport in organic semiconductors and interfaces. This is a very important step in guiding future device design and engineering.
M. G. Helander, Z. B. Wang, J. Qiu, and Z. H. Lu, “Band alignment at metal/organic and metal/oxide/organic interfaces”, Appl. Phys. Lett. 93, 193310 (2008).
Z. B. Wang, M. G. Helander, S. W. Tsang, and Z. H. Lu, “Abnormal charge injection behavior at metal-organic interfaces”, Phys. Rev. B78, 193303 (2008).
S.W. Tsang, D.W. Denhoff, Y. Tao, and Z.H. Lu, “Charge carrier induced barrier height reduction at organic heterojunctions”, Phys. Rev. B78, 081301(R) (2008).
H. Y. Yu, X. D. Feng, D. Grozea, Z. H. Lu, R. N. S. Sodhi, A-M. Hor and H. Aziz, “Surface Electronic Structure of Plasma-treated Indium Tin Oxides”, Appl. Phys. Lett. 78, 2595 (2001).
Lu has worked with several world leading experts from Bell Labs, Texas Instrument, Nortel networks, Stanford University, and National Research Council on physical understanding of gate dielectrics and interfaces, the key front-end technology for CMOS technology.
M. Lee, Z.H. Lu, W.T. Ng, D. Landheer, X. Wu, and S. Moisa, “Interfacial Growth in HfOxNy Gate Dielectrics Deposited Using [(C2H5)2N]4Hf with O2 and NO”, Appl. Phys. Lett. 83, 2638 (2003).
Z.H. Lu, J.P. McCaffrey, B. Brar, G.D. Wilk, B. Wallace, L.C. Feldman, and S.P. Tay, “Thickness Metrology of Ultra-Thin Gate SiO2 Films”, Appl. Phys. Lett. 71, 2764 (1997).
Z.H. Lu, S.P. Tay, R. Cao, and P. Pianetta, "The Effect of Rapid Thermal N2O-Nitridation on the Oxide/Si(100) Interface Structure", Appl. Phys. Lett. 67, 2836 (1995).
Surface passivation is a key step in many aspects of semiconductor device performance such as high-powered laser facet passivation, and is also a critical first step in semiconductor device manufacturing such as epitaxial growth. He has contributed significantly to the understanding of many important semiconductor surfaces.
Z.H. Lu, "Air-stable Cl-terminated Ge(111)", Appl. Phys. Lett. 68, 520 (1996).
J.M. Jin, M.W.C. Dharma-wardana, D.J. Lockwood, G.C. Aers, Z.H. Lu, and L.W. Lewis, "Surface Structure, Lattice Dynamics and Raman Spectroscopy of Sulphur Passivated InP(100)", Phys. Rev. Lett. 75, 878 (1995).
Z.H. Lu, M.J. Graham, X.H. Feng, and B.X. Yang, "Structure of S-passivated InP(100)-(1x1) Surface", Appl. Phys. Lett. 60, 2773 (1992).
Z.H. Lu, K. Griffiths, P.R. Norton, and T.K. Sham, "Adsorption of Atomic Hydrogen on Si(100) Surface", Phys. Rev. Lett. 68, 1343 (1992).
As Stanford’s Prof. D.A.B. Miller commented in Nature (Vol. 378, p.238, 1995), "Optoelectronics is becoming increasingly important for handling information. Long-distance telecommunications are now dominated by optical fibres. Semiconductor lasers are key to compact discs for information storage. Lasers and light-emitting diodes are used in many printers, and in display devices such as liquid crystal panels and indicator lights... The work of Lu and colleagues is an important demonstration of potentially useful properties of these silicon-based structures. Their work will surely stimulate more activity in this field and may yet give silicon an even brighter future.” Lu has made seminal breakthrough in discovering new way to make quantum-confined silicon emitting light.
Z.H. Lu and D. Grozea, "Crystalline Si/SiO2 Quantum Wells", Appl. Phys. Lett. 80, 255 (2002).
D.J. Lockwood, Z.H. Lu, and J.-M. Baribeau, "Quantum Confined Luminescence in Si/SiO2 Superlattices", Phys. Rev. Lett. 76, 539 (1996).
Z.H. Lu, D.J. Lockwood, and J.-M. Baribeau, "Quantum Confinement in and Light Emission from SiO2/Si Superlattices", Nature 378, 258, (1995).
His group has been collaborating with leading materials chemistry groups on developing novel nano-materials for electronic and optoelectronic applications.
K. Hou, D. Puzzo, M.G. Helander, S.S. Lo, L.D. Bonifacio, W. Wang, Z.H. Lu, G.D. Scholes, G.A. Ozin, “Dye-Anchored Mesoporous Antimony-Doped Tin Oxide Electrochemiluminescence Cell”, Adv. Mater. 21, 1 (2009).
K. Liu, C.L. Ho, S. Aouba, Y.Q. Zhao, Z.H. Lu, S. Petrov, N. Coombs, P. Dube, H.E. Ruda, W.Y. Wong, and I. Manner, “Synthesis and lithographic patterning of FePt nanoparticles using bimetallic metallopolyyne precursor”, Angewange Chemie 47, 1255 (2008).
D.A. Rider, K. Liu, J.C. Eloi, L. Vanderark, L. Yang, J. Wang, D. Grozea, Z.H. Lu, T.P. Russell, and I. Manner, “Nanostructured Magnetic Thin Films from Organometallic Block Copolymers:Pyrolysis of Self-Assembled Polystyrene-block-poly(ferrocebylethylmethylsilane)”, ACS Nano 2, 263 (2008).
K. Liu, C.L. Ho, S. Aouba, Y.Q. Zhao, Z.H. Lu, S. Petrov, N. Coombs, P. Dube, H.E. Ruda, W.Y. Wong, and I. Manners, “Synthesis and Lithographic Patterning of FePt Nanoparticles Using a Bimetallic Metallopolyyne Precursor”, Angewandte Chemie 46, 1 (2007).
C.A. Jaska, T.J. Clark, S.B. Clendenning, D. Grozea, A. Turak, Z.H. Lu, and I. Manners, “Poisoning of Heterogeneous, Late Transition Metal Dehydrocoupling Catalysts by Boranes and Other Group 13 Hydrides”, J. Am. Chem. Soc. 127, 5116 (2005).
S. Clendenning, S. Han, N. Coombs, C. Paquet, M. Rayat, D. Grozea, P. Broderson, R. Sodhi, C. Yip, Z.H. Lu, and I. Manners, “Magnetic Ceramic Films from a Metallopolymer Resist Using Reactive Ion Etching in a Secondary Magnetic Field”, Advanced Materials 16, 291 (2004).
S. Clendenning, S. Aouba, M. Rayat, D. Grozea, J.B. Sorge, P. Broderson, R. Sodhi, Z.H. Lu, C.M. Yip, M.R. Freeman, H.E. Ruda, and I. Manners, “Direct Writing of Patterned Ceramics Using Electron-beam Lithography and Metallopolymer Resists”, Advanced Materials 16, 215 (2004).
J. He, Z.H. Lu, S. Mitchell, and D.M. Wayner, "Self-assembled Alkyl Monolayers on Ge(111)", J. Am. Chem. Soc. 120, 2660 (1998).