The photonic perspective of organic light-emitting transistors

Organic light-emitting field-effect transistors (OLETs) are emerging as an innovative class of multifunctional devices that integrates the electronic properties of a transistor, the light-generation capability and the full potential of organic photonics. Recent significant advances, including the demonstration of OLET external quantum efficiency outperforming that of OLEDs based on the same emitting layer, brought the field at a stage where a full technology platform can be developed. The most advanced OLET structures encompass a huge technological potential for the realization of intense nanoscale light sources and highly integrated optoelectronic multifunctional systems. This article will give an overview of the current state-of-the-art of OLETs from the point of view of their photonic characteristics. In particular, the different device structures realized, the materials used and the strategies implemented to integrate optical resonators and waveguiding structures into light-emitting field-effect transistors will be reviewed and the main findings discussed. (Picture: Courtesy of E. T. C. srl)