Metallurgical and Materials Engineering  
 
H. Emrah Ünalan

Assist. Prof. Dr. H. Emrah Ünalan

Room: D-102

Tel: +90 (312) 210-5939
Fax: +90 (312) 210-2518

E-mail: unalan@metu.edu.tr

Personal Web Page
Research Group Web Page

Research Interests:

  • Large Area and Flexible Electronics
  • Organic Electronics and Semiconducting Devices
  • Nanowires and Carbon Nanotubes
  • Solar cells, Light Emitting Diodes and Batteries
Selected Publications:

  • Polyol Synthesis of Silver Nanowires: An Extensive Parametric Study, S. Coskun, B. Aksoy, H.E. Unalan, Crystal Growth & Design 11 (2011) 4963
  • Enhanced Supercapacitors From Hierarchical Carbon Nanotube and Nanohorn Architectures , P. Hiralal, H. Wang, H.E. Unalan, Y. Liu, M. Rouvala, D. Wei. P. Andrew, G.A.J. Amaratunga, J. Mater. Chem. 21 (2011) 17810.
  • Silicon nanowire – Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) heterojunction solar cells, B. Ozdemir, M. Kulakci, R. Turan, H.E. Unalan, Appl. Phys. Lett. 99 (2011) 113510..
  • Thin Film Transistors Based on Poly(3,3’’’-dialkyl-quarterthiophene) and Zinc Oxide Nanowires with Improved Ambient Stability, S.M.C. Vieira, G.W. Hsieh, H.E. Unalan, G.A.J. Amaratunga, W.I. Milne, S. Dag, L.W. Wang, Appl. Phys. Lett. 98 (2011) 102106.
  • Effect of Electroless Etching Parameters on the Growth and Reflection Properties of Silicon Nanowires, B. Ozdemir, M. Kulakci, R. Turan, H.E. Unalan, Nanotechnology 22 (2011) 155606.
  • The Mechanism of the Sudden Termination of Carbon Nanotube Supergrowth, X. Wang, Y. Feng, H.E. Unalan, G. Zhong, P. Li, H. Yu, A.I. Akinwande, W.I. Milne, Carbon 49 (2011) 214.
  • P. Hiralal, S. Imaizumi, H.E. Unalan, H. Matsumoto, M. Minagawa, M. Rouvala, A. Tanioka, G.A.J. Amaratunga, “Nanostructure enhanced all-solid, flexible batteries”, ACS Nano 4 (2010) 2730.
  • S. Santra, P.K. Guha, S.Z. Ali, P. Hiralal, H.E. Unalan, J.A. Covington, G.A.J. Amaratunga, W.I. Milne, J.W. Gardner, F. Udrea, “ZnO nanowires grown on SOI CMOS substrate for ethanol sensing”, Sens. Act. B 146 (2010) 559.
  • C. Li, Y. Zhang, M. Mann, P. Hiralal, H.E. Unalan, W. Lei, B.P. Wang, D.P. Chu, D. Pribat, G.A.J. Amaratunga, W.I. Milne, “Stable, self-ballasting field emission from zinc oxide nanowires grown on an array of vertically-aligned carbon nanofibres”, Appl. Phys. Lett. 96 (2010) 143114.
  • E.P.J. Parrott, J.A. Zeitler, J. McGregor, S.P. Oei, H.E. Unalan, W.I. Milne, J.P. Tessonnier, D.S. Su, R. Schlogl, L.F. Gladden, “The Use of Terahertz Spectroscopy as a Sensitive Probe in Discriminating the Electronic Properties of Structurally Similar Multiwalled Carbon Nanotubes”, Adv. Mater. 21 (2009) 3953.
  • E.P.J. Parrott, J.A. Zeitler, J. McGregor, S.P. Oei, H.E. Unalan, S.C. Tan, W. I. Milne, J.P. Tessonnier, R. Schlogl, L.F. Gladden, "Understanding the Dielectric Properties of Heat Treated Carbon Nanofibers at Terahertz Frequencies: a New Perspective on the Catalytic Activity of Structured Carbonaceous Materials", J. Phys. Chem. C. 113 (2009) 10554.
  • H.E. Unalan, Y. Zhang, P. Hiralal, S. Dalal, D. Chu, G. Eda, K.B.K. Teo, M. Chhowalla, W.I. Milne, G.A.J. Amaratunga, "Zinc Oxide Nanowire Networks for Macroelectronic Devices", Appl. Phys. Lett. 94 (2009) 163501.
  • N. Wang, K. Yano, C. Durkan, N. Plank, M.E. Welland, Y. Zhang,H.E. Unalan, M. Mann, G.A.J. Amaratunga, W.I. Milne, "Direct Measurement of Charge Transport Through Helical Poly (ethyl propiolate) Nanorods Wired Into Gaps in Single Walled Carbon Nanotubes", Nanotechnology 20 (2009) 105201.
  • G. Eda, H.E. Unalan, N. Rupesinghe, G.A.J. Amaratunga, M. Chhowalla, "Field Emission from Graphene Based Composite Thin Films", Appl. Phys. Lett. 93 (2008) 233502.
  • H.E. Unalan, Y. Yang, Y. Zhang, P. Hiralal, D. Kuo, S. Dalal, T. Butler, S.N. Cha, J.E. Jang, K. Chremmou, G. Lentaris, D. Wei, R. Rosentsveig, K. Suzuki, H. Matsumoto, M. Minagawa, Y. Hayashi, M. Chhowalla, A. Tanioka, W.I. Milne, R. Tenne, G.A.J. Amaratunga, "ZnO Nanowire and WS2 Nanotube Electronics", IEEE Transactions on Electron Devices 55 (2008) 2988 (Invited Review).
  • F.M. Li, G.W. Hsieh, S. Dalal, M.C. Newton, J.E. Scott, P. Hiralal, A. Nathan, P.A. Warburton, H.E. Unalan, P. Beecher, A.J. Flewitt, I. Robinson, G.A.J. Amaratunga, W.I. Milne, "Zinc Oxide Nanostructures and High Electron Mobility Nanocomposite Thin Film Transistors", IEEE Transactions on Electron Devices 55 (2008) 3001 (Invited Review).
  • H.E. Unalan, P. Hiralal, D. Kuo, B. Parekh, G.A.J. Amaratunga, M. Chhowalla "Flexible Organic Photovoltaics from Zinc Oxide Nanowires Grown on Transparent and Conducting Single-Walled Carbon Nanotube Films", J. Mater. Chem. 18 (2008) 5909.
  • P. Hiralal, H.E. Unalan, U.K.G. Wijayantha, J.M. Driscoll, G.A.J. Amaratunga, "Growth and Process Conditions of Aligned and Patternable Films of Iron (III) Oxide Nanowires by Thermal Oxidation of Iron", Nanotechnology 19 (2008) 455608.
  • H.E. Unalan, D. Wei, K. Suzuki, S. Dalal, P. Hiralal, H. Matsumoto, S. Imaizumi, M. Minagawa, A. Tanioka, A.J. Flewitt, W.I. Milne, G.A.J. Amaratunga, "Photoelectrochemical Cell Using Dye Sensitized Zinc Oxide Nanowires Grown on Carbon Fibers", Appl. Phys. Lett. 93 (2008) 133116.
  • D. Wei, H.E. Unalan, D. Han, Q. Zhang, L. Niu, G.A.J. Amaratunga, T. Ryhanen, "A Solid-State Dye-Sensitized Solar Cell Based on a Novel Ionic Liquid Gel and ZnO Nanoparticles on a Flexible Polymer Substrate", Nanotechnology 19 (2008) 424006.
  • H.E. Unalan, P. Hiralal, N. Rupesinghe, S. Dalal, W.I. Milne, G.A.J. Amaratunga, "Rapid Synthesis of Aligned Zinc Oxide Nanowires", Nanotechnology 19 (2008) 255608 (Media coverage: Nanotechweb.org).
  • G. Fanchini, H.E. Unalan, M. Chhowalla, "Electric Field Dependence of Raman Active Modes in Single Wall Carbon Nanotube Thin Film Networks", Nano Letters 7 (2007) 1129.
  • G. Fanchini, H.E. Unalan, M. Chhowalla, "Modification of Transparent and Conducting Single Walled Carbon Nanotube Thin Films via Bromine Functionalization", Appl. Phys. Lett. 90 (2007) 092114.
  • G. Fanchini, H.E. Unalan, M. Chhowalla, "Optoelectronic Properties of Transparent and Conducting Single Wall Carbon Nanotube Thin Films", Appl. Phys. Lett. 88 (2006) 191919.
  • H.E. Unalan, G. Fanchini, A. Kanwal, A. Du Pasquier, M. Chhowalla, "Design Criteria for Transparent Single Walled Carbon Nanotube Thin Film Transistors", Nano Letters 6 (2006) 677.
  • A. Du Pasquier, H.E. Unalan, A. Kanwal, S. Miller, M. Chhowalla, "Conducting and Transparent Single Walled Carbon Nanotube Electrodes for P3HT-PCBM Plastic Solar Cells", Appl. Phys. Lett. 87 (2005) 203511.
  • M. Chhowalla, H.E. Unalan, Y. Wang, Z. Iqbal, K. Park, F. Sesti, "Irreversible Blocking of Ion Channels Using Functionalized Single-Walled Carbon Nanotubes", Nanotechnology 16 (2005) 2982.
  • H.E. Unalan, M. Chhowalla, "Investigation of Single-Walled Carbon Nanotube Growth Parameters Using Alcohol Chemical Vapor Deposition", Nanotechnology 16 (2005) 2153.
  • M. Chhowalla, H.E. Unalan "Thin Films of Hard Cubic Zr3N4 Stabilized by Stress", Nature Materials 4 (2005) 317 (Featured in Science).