Pixeled Electroluminescence from Multilayer Heterostructure Organic Light-Emitting Transistors

Improved performance of multilayer heterostructure organic light-emitting transistors (OLETs) was observed in brightness and external quantum efficiency (EQE) by inserting an ultrathin MoO_<i>x</i> layer and TPBI buffer layer. With in-plane emission mainly beneath the drain electrode with a maximum width of 120 μm, an EQE of 0.16% at a brightness of 238 cd/m² was obtained. Different sizes of pixeled OLETs were fabricated by restricting the pixel length by narrowing the width of the gate electrode perpendicular to the source/drain electrodes. Light emission pixels with sizes from 25 to 400 μm have been successfully demonstrated. The maximum width of the emission zone was not affected, and the maximum EQE and the corresponding brightness presented an increasing tendency for pixeled OLETs. The results in our work are helpful for developing a new generation of OLET-based display technology