Electrical characterization of Al/PTF/PEDOT:PSS/ITO heterojunction structure Hatice Kanbur C ¸ avus ¸ 1 Received: 16 March 2015 / Accepted: 4 April 2015 Ó Springer Science+Business Media New York 2015 Abstract We have investigated electrical properties of Al/PTF/PEDOT:PSS/ITO heterojunction structure at room temperature. Firstly, optical properties of the polymer [poly(pentachlorophenyl methacrylate)] were determined from ultraviolet–visible absorption spectra in the wave- length range of 200 to 700 nm. Optical band gap (E g ) of the polymer was found about 4.70 eV. Secondly, the PED- OT:PSS and polymer thin film (PTF) were prepared on the ITO substrate. The current transport mechanism and elec- trical parameters of Al/PTF/PEDOT:PSS/ITO heterojunc- tion structure were investigated using current–voltage (I– V) characteristics. 1 Introduction Functional electronic and optoelectronic devices require new materials with specific properties. Polymers are of great interest because of their unusual electrical and optical properties. In most cases, polymer electronic devices are laminar. In other words, they are printed or otherwise ap- plied as thin film on surfaces. This productions with low cost and low temperature open as wide field of applica- tions, such as displays, Schottky diodes, organic light emitting diode (OLED), organic solar cells etc. [1–9]. There are different deposition methods to obtain thin film of polymer materials. These methods are electrochemical deposition, spin coating, dry technique and Langmuir– Blodgett (LB) deposition etc. [8, 9]. Spin coating deposition is the easiest and best studied route to producing efficient polymer thin film at the present. Many kinds of polymers have been synthesized and now utilized in wide variety of fields. In this paper, poly(pen- tachlorophenyl methacrylate) was studied. This polymer has a refraction index (1.608) enough for optoelectronic applications. The other polymer used in this study is PEDOT-PSS. PEDOT:PSS [poly(3,4-ethylene dioxythio- phene):poly(styrene sulfonate)] is a conductive polymer [8, 9]. Part of the sulfonyl groups are deprotonated and carry a negative charge. The other component poly(3,4-ethylene- dioxythiophene) or PEDOT is a conjugated polymer and carries positive charges and is based on polythiophene. PEDOT:PSS is easily process able into thin films from aqueous solution and has high strength, flexibility, excel- lent thermal, mechanical, and environmental stability. It is used as a transparent, conductive polymer with high duc- tility in different applications. Because PEDOT:PSS pre- vents the electrostatic discharges during film rewinding, reduces dust buildup after processing and has high trans- parency in the visible range [10, 11]. Therefore, the aim of this study is to obtain the characteristics parameters of Al/ PTF/PEDOT:PSS/ITO heterojunction structure. 2 Experimental details Poly(pentachlorophenyl methacrylate) was obtained from Sigma Aldrich company. Molecular structure of polymer is shown in Fig. 1. Poly(pentachlorophenyl methacrylate) was dissolved in chloroform solution and the UV–Vis spectrum of polymer was obtained using a Hach Lange DR 5000 UV–Vis Spectrophotometer (wavelength range 200–700 nm). Then, Al/PTF/PEDOT:PSS/ITO hetero- junction structures was fabricated. The fabrication process & Hatice Kanbur C ¸ avus ¸ hatice.kanbur@bozok.edu.tr 1 Department of Physics, Bozok University, Yozgat, Turkey 123 J Mater Sci: Mater Electron DOI 10.1007/s10854-015-3045-9