Efficient and Stable Solution-Processed Organic Light-Emitting Transistors Using a High‑k Dielectric

We report the development of highly efficient and stable solution-processed organic light-emitting transistors (OLETs) that combine a polymer heterostructure with the transparent high-k dielectric poly­(vinylidenefluoride_0.62-trifluoroethylene_0.31-chlorotrifluoroethylene_0.7) (P­(VDF-TrFE-CTFE)). The polymer heterostructure comprises of poly­[4-(4,4-dihexadecyl-4H-cyclopenta­[1,2-b:5,4-b’]­dithiophen-2-yl)-alt-[1,2,5]­thiadiazolo­[3,4-c]­pyridine] (PCDTPT) and Super Yellow as charge-transporting and light-emitting layers, respectively. Device characterization shows that the use of P­(VDF-TrFE-CTFE) leads to larger channel currents (≈2 mA) and lower operating voltages (−35 V) than for previously reported polymer based OLETs. Furthermore, the combined transparency of the dielectric and gate electrode, results in efficient bottom emission with external quantum efficiency of ≈0.88% at a luminance L ≥ 2000 cd m^–2. Importantly, the resulting OLETs exhibit excellent shelf life and operational stability. The present work represents a significant step forward in the pursuit of all-solution-processed OLET technology for lighting and display applications.