LED switching module with organic devices

摘要

The paper aims to describe the fabrication of organic transistors and their integration into hybrid circuits on flexible substrates. Organic thin film transistors (OTFT) are fabricated using commercially available materials. The Au S-D electrodes are realized by photolithography, while the organic semiconductor and organic dielectric layers are spin-coated. Finally, the Au gate electrode is evaporated in order to obtain a Bottom Contact Top Gate OTFT architecture. The paper presents a prototype realized in classic technology on rigid substrate, which is used to perform a PSpice simulation of the circuit. After the PSpice simulation, a module on PET substrate is made with organic transistors. Two transistors are employed to build the inverter used to switch the LED, while a third transistor is diode connected and acts as a 10MOhms resistor. The electrical characterization of the transistors and measurements onto the module are performed with a 4200 Keithley Semiconductor Analyzer. An SMD LED, in 0402 package, is used and all interconnections are done manually using Silver conductive paste, which dries at room temperature. The paper describes the circuit simulation and layout realization.