High-Mobility, Heterostructure Light-Emitting Transistors and Complementary Inverters

Light-emitting field effect transistors (LEFETs) are optoelectronic devices that can simultaneously execute light emission and the standard logic functions of a transistor in a single device architecture. In this article, we show that ambipolar LEFETs can be made in a bilayer structure using Super Yellow, a light-emitting polymer layer, and a high-mobility diketopyrrolo-pyrrole-based copolymer as an ambipolar charge-transporting layer. The LEFETs were fabricated in the bottom gate architecture with top-contact, air-stable, symmetric Au–Au electrodes. The devices show light emission in both electron and hole accumulation modes with an external quantum efficiency (EQE) of 0.1% at a brightness of 650 cd/m 2 in electron accumulation mode, and an EQE of 0.001% at a brightness of 4 cd/m 2 in hole accumulation mode. We have also demonstrated a light-emitting inverter by combining two LEFETs into the inverter architecture. The light-emitting inverter generates both electrical and optical signals with an electrical gain of 112.