Solution‐Processed Organic Light‐Emitting Transistors Incorporating Conjugated Polyelectrolytes

Improved performance of p‐type organic light‐emitting transistors (OLETs) is demonstrated by introducing a conjugated polyelectrolyte (CPE) layer and symmetric high work function (WF) source and drain metal electrodes. The OLET comprises a tri‐layer film consisting of a hole transporting layer, an emissive layer, and a CPE layer as an electron injection layer. The thickness of the CPE layer is critical for achieving good performance and provides an important structural handle for consideration in future optimization studies. We also demonstrate for the first time, good performance solution‐processed blue‐emitting OLETs. These results further demonstrate the simplification of device fabrication and improved performance afforded by integrating CPE interlayers into organic optoelectronic devices.