Study on the Photoresponse Characteristics of Organic Light-Emitting Field-Effect Transistors

Organic photodetectors have attracted great attention because of their promising applications in the fields of imaging, optical communication, and biosensing. Although the optical and electrical performances of the organic light-emitting field effect transistors (OLEFETs) have improved substantially in the past decade, the photodetection property of the OLEFETs has rarely been studied. Here, we investigated the photoresponse characteristics of the heterostructured OLEFETs, which unexpectedly shows performance comparable to some organic phototransistor-only devices, without sacrificing the light emission performance of the device. The device shows photoresponse ability in a wide visible light range and a maximum photon-to-electron efficiency of 45 300% with millisecond-scale switching on and off time when under the illumination of 405 nm. It is found that the photoresponse characteristics of the devices are mainly determined by the hole injection layer, as light absorption happens mainly in this layer. Our study would provide some insights into further exploring the light detection potential for the multifunctional OLEFETs, which might meet the requirements for future high integration, low-weight, and low-cost applications.