Roger Prétôt

High-performance flexible bottom-gate organic field-effect transistors with gravure printed thin organic dielectric

One of the key advantages of organic field-effect transistors (OFETs) is their ability to form flexible, conformable and lightweight electronic devices, e.g. radio frequency identification (RFID) tags,[1] microprocessors[2] and flexible displays.[3] These require fabrication over large-areas on flexible plastic substrates, the poor dimensional stability of such substrates creating the additional demand of low-temperature processing (<200 °C).[4] While high performance source, drain and gate electrodes and interconnects require metal evaporation under vacuum, ideally the dielectric and organic semiconductor (OSC) should be processed from solution under ambient conditions to reduce fabrication costs. Regarding device architecture, OFETs with a bottom-gate (BG) bottom-contact (BC) geometry (Figure ​1c)1c) have an advantage in that the organic semiconducting layer is deposited last.[5] This affords easy fabrication and patterning of micron-scale OFET channels, electrodes and interconnects by conventional photolithographic methods, whilst avoiding exposure of the active OSC material to UV radiation and aggressive or solubilising chemicals. Furthermore, this architecture is compatible with vacuum sublimation or vapour phase techniques for OSC deposition, allowing access to a wide range of high-performance materials. Such OFETs can form the building blocks of high performance, low-cost electronic circuitry.

59.1: Invited Paper: Optoelectronic OLED Modeling for Device Optimization and Analysis

Organic light-emitting devices (OLEDs) consist of a stack of multiple thin film layers whose thicknesses influence both the optical and electronic performance. Upon injection and transport, the charge carriers may recombine to form excitons that diffuse and decay radiatively, thus leading to distinct recombination and emission zone profiles that determine device performance. Suitable simulation tools that allow a better understanding and efficient optimization of organic optoelectronics devices and materials are desirable.