Fabrication and Characterization of Polyaniline Based Schottky Diode Asgar Hajibadali, Majid Baghaei Nejhad Faculty of Electrical and Computer engineering Hakim Sabzevari University Sabzevar, Iran asgar.haji@gmail.com Gholamali Farzi Department of Material and Polymer engineering Hakim Sabzevari University Sabzevar, Iran Hashem Hojjati Rad Department of Information technology and Communication Payame noor University of Tehran Tehran, Iran Abstract—In this work polyaniline was chemically synthesized. Schottky diode was fabricated based on polyaniline as p- type semiconductor, gold as Ohmic contact and aluminum as Schottky contact. Coating of metals was carried out with physically vapour deposition method and coating of polymer was done with solvent casting method. Current-voltage (I-V) characteristics of diode were measured and current transport mechanism of diode was studied. I-V characteristics showed that Schottky diode based on pure polyaniline follows the thermionic emission mechanism. The electronic parameters of Schottky diode such as ideality factor, barrier height and reverse saturation current have been determined. I. INTRODUCTION Electrical conductivity of conjugated polymers can be varied over the wide range from insulator to semiconductor and to conductor through p- doping or n- doping. In the recent decades lots of research works have been carried out on the use of conducting polymers such as polyaniline (PANI) [1], polypyrrole [2], polythiophen [3], and etc. as active materials in electronic devices. Several devices have been made from this polymers, such as field effect transistor (FETs) [4], [5], Schottky diodes [6]-[8], light emitting diodes (LEDs) [9], [10], photovoltaic cells [11]. Among the conducting polymers, polyaniline has received great attention due to its good thermal and environmental stability, unique properties in conducting form and its ability to tune the electronic properties by careful choice of chemical and electrochemical preparative routes. Rectifying metal-semiconductor Schottky junction diodes compared with p-n junction diodes have benefits such as higher switching speeds, lower noise level, lower forward resistance and intrinsic suitability for low-voltage, high- current applications [12]. Several research groups have illustrated fabrication of Schottky diodes based on polyaniline using vacuum deposition [13], solvent casting [14]-[16], electro polymerization [17], [18], and pellets [19]. In this work, polyaniline was chemically synthesized, Schottky diode with Al-PANI-Au structure was fabricated, current-voltage (I-V) characteristics of diode were measured, current transport mechanism was studied and electronic parameters of fabricated Schottky diode were determined. II. EXPERIMENTAL DETAILS A. Materials Aniline was supplied from Merck and was distilled prior to synthesis. Hydrochloric acid (HCl), Ammonium persulfate (APS), and N-methyl-2-pyrrolidinone (NMP), purchased from Merck and were used as received. B. Instrumentation Gold and aluminum were physically vapour deposited with PVD-EMS-160. Gold was coated on test glass by thermal- resistance evaporation technique and aluminum was coated on polyaniline film by electron beam gun evaporation technique. 978-1-4673-5634-3/13/$31.00 ©2013 IEEE