Design and Construction of Home-Made Spin Coater for OLED Production

Abstract

This study devotes to the design and fabrication of a spin coating equipment using locally available materials for the deposition of uniform thin films on several substrates and also the production of organic light emitting diodes (OLEDs) using this home-made device. The equipment consists of a brushed direct current (BDC) motor with high speed, chuck (substrate holder) and regulated power supply. The system has manual control, wide spin speed ranging from 500 to 6500 revolutions per minute (rpm), spin speed stability and compact size. The spin speed stability has been determined by a tachometer against the spinning time. The performance of our equipment was tested for coating Poly (3,4-ethylene dioxythiophene)poly (styrene sulfonate) (PEDOT:PSS) polymer. Three different PEDOT:PSS thin films were successfully deposited on glass substrates that are standard products, using the spin speeds of 1000, 2000 and 3000 revolutions per minutes (rpm). Also, under similar experimental conditions, PEDOT:PSS films were prepared by a commercial spin coater. These two group samples have been characterized by optical and atomic force microscope (AFM) measurements and compared with each other. Furthermore, in order make an OLED, a multilayer system consisting of, in sequence, PEDOT:PSS, poly[2-methoxy-5-(2`-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and Tris (8-hydroxyquinolinato) Aluminium (Alq3) layers was fabricated on commercial indium tin oxide (ITO)/glass substrates using both our home-made and a commercial spin coater. The top layers of all samples were covered by the Al using thermal evaporation. The current-voltage (I-V) characteristics of OLED samples prepared by two different devices were examined. The obtained data showed that OLEDs could successfully be produced by our homemade spin coater.