A new bright future for organic light-emitting transistors

The rapid advancement of organic semiconductors has fueled the remarkable growth of organic electronic devices, including organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs), and organic photovoltaics (OPV). Looking ahead, the evolution of organic optoelectronic devices is moving toward cost-effective, highly integrated, and flexible solutions with multifunctional capabilities, further expanding the range of potential applications.

Organic light-emitting transistors (OLETs) represent a novel class of devices combining the gate modulation functionality of OFETs with the light-emitting properties of OLEDs, demonstrating significant promise for efficient next-generation displays, smart sensing, and optical communication systems (Figure 1A). However, OLET development has lagged behind other organic electronic devices due to the lack of suitable active materials that can simultaneously achieve high charge carrier mobility and strong solid-state emission, as well as the absence of mature device fabrication technologies. In recent years, substantial progress has been made in developing high-mobility emissive organic semiconductors and enhancing OLET device performance.1 Notably, the gate modulation capability of OLETs has been shown to significantly improve electric-to-optical conversion efficiency, surpassing that of conventional OLEDs. An external quantum efficiency (EQE) exceeding 20% has been proposed, originating from a novel vertical OLET structure.2 Moreover, OLETs have exhibited additional functionalities, such as optically switchable properties3 and intrinsic linear polarization,4 further expanding their potential applications.