Low optical turn-on voltage in solution processed hybrid light emitting transistor

Abstract

Low optical turn-on voltage is realized in a solution processed hybrid light emitting transistor (LET). To achieve that, an original approach has been applied where an emissive polymer is mixed with a hole transport small molecule. While the high mobility solution processed oxide determines the main electrical characteristics of the transistor as the electron transport layer, the hole transport molecule acts as an immediate source of positive charges to the emissive polymer within its matrix, thus resulting in more efficient light emission when the transistor is turned-on electrically. While the electrical turn-on voltage remains almost the same, the light turn-on voltage significantly decreases from 27 V in the control device to 2 V in the blend device. Furthermore, brightness and external quantum efficiency are also considerably improved within the whole range of gate bias in the blend device, evidencing that our approach enhances overall optical performance of a solution processed hybrid LET.