MÜHENDİSLİK FAKÜLTESİMETALURJİ VE MALZEME MÜHENDİSLİĞİ


H. Emrah Ünalan

Assoc. Prof. Dr. H. Emrah Ünalan
Room No: 
D-102
Telephone: 
+90 (312) 210-5939
Fax: 
+90 (312) 210-2518
E-posta: 
unalan@metu.edu.tr
Research Interests: 
  • Flexible Electronics
  • Organic Electronics and Semiconducting Devices
  • Nanowires and Carbon Nanotubes
  • Solar cells, Light Emitting Diodes and Batteries
Publications: 
  • Metal-Enhanced Fluorescence from Silver Nanowires with High Aspect Ratio on Glass Slides for Biosensing Applications, B. Abel, S. Coskun, M. Mohammed, R. Williams, H. E. Unalan, K. Aslan, J. Phys. Chem. C 119 (2015) 675.
  • Nanowire-based Multifunctional Antireflection coatings for Solar cells, P. Hiralal, C. Chien, N.N. Lal, H. Butt, H. Zhou, H.E. Unalan, J.J Baumberg, G.A.J. Amaratunga, Nanoscale 6 (2014) 14555.
  • Zinc Oxide  Nanowire Decorated Single Use Electrodes for Electrochemical DNA Detection, G. Congur, E. Ates, A. Afal, H.E. Unalan, A. Erdem, J. Am. Ceram. Soc. 98 (2014) 663.
  • Transparent and flexible supercapacitors with single walled carbon nanotube thin film electrodes, R. Yuksel, Z. Sarioba, A. Cirpan, P. Hiralal, H.E. Unalan, ACS Appl. Mater. Interfaces 6 (2014) 15434.
  • Indium rich InGaN solar cells grown by MOCVD, H. Çakmak, E. Arslan, M. Rudzinski, P. Demire, H. E. Unalan, W. Strupinski, R. Turan, M. Öztürk, E. Özbay, J Mater Sci: Mater Electron 25 (2014) 3652.
  • Influence of thermal annealing on microstructural, morphological, optical properties and surface electronic structure of copper oxide thin films, G. Akgul, F.A. Akgul, N. Yildirim, H. E. Unalan, R. Turan, Mat. Chem. Phys. 147 (2014) 987.
  • Germanium Nanowire Synthesis Using Solid Precursors, B. Aksoy, Y.E. Kalay, H.E. Unalan, J. Cryst. Growth 392 (2014) 20.
  • Periodic Nanopillar Photovoltaic Arrays in n-i-p Amorphous Si using Carbon Nanotube Scaffolds, H. Zhou, F. Tao, P. Hiralal, A. Ahnood, H.E. Unalan, A. Nathan, G.A.J. Amaratunga, accepted for IEEE Trans. Nano (2014).
  • Fabrication and characterization of copper oxide-silicon nanowires heterojunction photodiodes, G. Akgul, E. Mulazimoglu, F.A. Akgul, H.E. Unalan, R. Turan, J. Phys. D: Appl. Phys. 47 (2014) 065106.
  • Enhanced Localized Surface Plasmon Resonance Obtained in Two Step Etched Silicon Nanowires Decorated with Silver Nanoparticles, E. Mulazimoglu, G. Nogay, R. Turan, H.E. Unalan, Appl. Phys. Lett. 103 (2013) 143124.
  • Hierarchically structured nanocarbon electrodes for flexible solid lithium batteries, D. Wei, P. Hiralal, H. Wang, H. E. Unalan, M. Rouvala, I. Alexandrou, P. Andrew, T. Ryhänen, G. A. J. Amaratunga, Nano Energy 2 (2013) 1054.
  • Silicon Nanowire Network Metal-Semiconductor-Metal Photodetectors, E. Mulazimoglu, S. Coskun, M. Gunoven, B. Butun, E. Ozbay, R. Turan, H.E. Unalan, Appl. Phys. Lett. 103 (2013) 083114.
  • Silicon nanowire—silver indium selenide heterojunction photodiodes, M. Kulakci, T. Colakoglu, B. Ozdemir, M. Parlak, H.E. Unalan, R. Turan, Nanotechnology 24 (2013) 375203.
  • Performance of Nanowire Decorated Mono- And Multi-Crystalline Si Solar Cells, F. Es, O. Demircioglu, M. Günöven, M. Kulakcı, H. E. Unalan, R. Turan, Physica E 51 (2013) 71.
  • Optimization of Silver Nanowire Networks for Polymer Light Emitting Diode Electrodes, S. Coskun, E.S. Ates, H.E. Unalan, Nanotechnology 24 (2013) 125202.
  • Highly efficient room temperature synthesis of silver-doped zinc oxide (ZnO:Ag) nanoparticles: Structural, optical and photocatalytic properties, O. Yildirim, H.E. Unalan, C. Durucan, J. Am. Ceram. Soc. 96 (2013) 766.
  • All Solution Processed, Nanowire Enhanced UV Photodetectors, A. Afal, S. Coskun, H.E. Unalan, Appl. Phys. Lett. 102 (2013) 043503.
  • Application of Si Nanowires Fabricated by Metal Assisted Etching to Crystalline Si Solar Cells, M. Kulakci, F. Es, B. Ozdemir, H.E. Unalan, R. Turan, IEEE PV 3 (2013) 548.
  • Zinc Oxide Nanowire Photodetectors with Single Walled Carbon Nanotube Thin Film Electrodes, E.S. Ates, S. Kucukyildiz, H.E. Unalan, ACS Applied Materials & Interfaces 4 (2012) 5142.
  • Optimization of Silver Nanowire Networks for Polymer Light Emitting Diode Electrodes, S. Coskun, E.S. Ates, H.E. Unalan, Nanotechnology 24 (2013) 125202.
  • ZnO Nanorods as Antireflective Coatings for Industrial Scale Single Crystalline Silicon Solar Cells, P.Aurang, O. Dericioglu, F. Es, R. Turan, H.E. Unalan, J. Am. Ceram. Soc. 96 (2013) 1253.
  • Transparent, Highly Flexible, All Nanowire Network Photodetectors, B. Aksoy, S. Coskun, S. Kucukyildiz, H.E. Unalan, Nanotechnology 23 (2012) 325202.
  • Hydrothermal Zinc Oxide Nanowire Growth Using Zinc Acetate Dihydrate Salt, M.C. Akgun, Y.E. Kalay, H.E. Unalan, J. Mater. Res. 27 (2012) 1445.
  • Nanowires for Energy Generation, P. Hiralal, H.E. Unalan, G.A.J. Amaratunga, Nanotechnology 23 (2012) 194002.
  • Zinc Oxide Nanowire Enhanced Multifunctional Coatings for Cotton Fabrics, E.S. Ates, H.E. Unalan, Thin Solid Films 520 (2012) 4658.
  • Nanowires for Energy Generation, P. Hiralal, H.E. Unalan, G.A.J. Amaratunga, Nanotechnology 23 (2012) 194002. 
  • Deposition of Carbon Nanotubes on CMOS, X. Wang, Y. Zhang, M.S. Haque, K.B.K. Teo, M. Mann, H.E. Unalan, P.A. Warburton, F. Udrea, W.I. Milne, IEEE Transactions on Nanotechnology 11 (2012) 215.
  • 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).