Organic light-emitting transistor as nanoscale light source for optical sensing

by Dr Stefano Toffanin (CNR (ISMN))




Organic light-emitting transistors (OLETs) show, in a single device, the fascinating combination of electrical switching characteristics and light generation capability. Thus, the OLET development is prompted by the possibility to exploit a transport geometry to suppress deleterious photon losses and exciton quenching mechanisms inherent in the OLED architecture, and ultimately enable new light source technologies at the nanoscale. The key advantages of the planar structure coupled to the possibility to easily incorporate photonic structures for light guiding, confinement and extraction, position favorably the field-effect transistor approach to achieve efficient and bright electroluminescence form organic semiconducting materials. Based on these characteristics organic light-emitting transistors are of immediate use in sensing platforms, optical communication and integrated optoelectronic systems, which incorporate OLETs as a key active element.
In particular, the feasibility of optical instruments for sensing depends not only on recognition or transduction principles but on the entire sensor system where cost and portability are of primary concern for effective point-of-care or in-the-field applications. The lack of an integrated, versatile detection scheme - one which is miniaturized, integrated, wavelength-selective and able to monitor multiple locations on the chip - is a major obstacle to the deployment of diagnostic devices in the real-setting applications and has prevented the development of more complex tests where rapid, kinetic or multipoint analysis is required.
In this oral contribution, we will review the latest experimental achievements in the design of the multiple components comprising the architecture of the OLET device (such as charge-transport and emissive layers1, functional interfaces2, light-extraction structures3) and in the investigation of the as-correlated charge-exciton interaction processes3, eventually aiming at the realization of a light-emitting source to be integrated into an innovative miniaturized photonic sensor for validated and in-field multiplexing screening of interest analytes for sustainable food safety and food quality.
This work has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 780839 (MOLOKO Project).


Organized by

Giorgio Keppel