Printable organic solid-state devices, including organic light-emitting diodes (OLEDs) and organic thin-film transistors (OTFTs) present a paradigm shift in manufacturing, cost and environmental impact when compared to the conventional inorganic technologies. OLEDs offer great versatility in the design of lighting systems based on large-area diffused light sources. In recent years, smarter lighting concepts have emerged at the crossroad of display technology and lighting that enable the control of the spatial distribution of light in real time. This adaptive illumination is enabled by combining segmented OLEDs with OTFTs. For these concepts to come to fruition, it is critical that further advances be made in improving the efficacy and stability of OLEDs and simultaneously in enhancing the performance and reliability of OTFTs. In this talk, we will discuss recent advances in developing new thermally activated delayed fluorescent materials and recent progress in OTFTs. In particular, we report on an exhaustive characterization of OTFTs with an ultra-thin bilayer gate dielectric comprising the amorphous fluoropolymer CYTOP and an Al2O3: HfO2 nanolaminate. The bilayer geometry results in two distinct aging mechanisms that through a compensation effect, yields devices with very low threshold voltage shifts. Modeling with a double stretched-exponential model predicts threshold voltage shift values in the range of 0.1 – 0.25 V over a period of ten years even at temperatures of 55 °C. The microcrystalline OTFTs with a bilayer gate dielectric exhibit carrier mobility values up to 1.6 cm2 V-1 s-1, a threshold voltage stability that is comparable or superior to that expected from commercial TFT technologies, and excellent environmental and thermal stability even after prolonged immersion in water.
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