Highly efficient hybrid light-emitting transistors incorporating MoOx/Ag/MoOx semi-transparent electrodes

Abstract

Light-emitting transistors (LETs) have recently emerged as a promising type of optoelectronic device which incorporates the switching function of a transistor with a light-emitting function. Zinc oxynitride (ZnON) based organic-inorganic hybrid LETs (HLETs) have recently shown excellent characteristics in this context, including very low threshold voltage (<5 V), high mobility (up to 5.3 cm(2) V-1 s(-1)) and brightness of 1.64 x 10(4) cd m(-2), a significant improvement compared to organic based LETs. Despite remarkably improved performance, the external quantum efficiency (EQE) of HLETs was similar to 0.1%, leaving room for additional improvement. To overcome the low EQEs of HLETs, we have investigated the electrical and optical characteristics of HLETs incorporating MoOx/Ag/MoOx semi-transparent electrodes with variable Ag layer thickness. HLETs with the architecture MoOx/Ag/MoOx (8/15/15 nm) exhibited an electron mobility of 1.06 cm(2) V-1 s(-1) with on/off ratio of 1.05 x 10(4), a maximum brightness of 2.09 x 10(4) cd m(-2) and a greatly improved EQE of up to 3.31%. This study provides valuable information about the electrical and optical properties of HLETs with oxide/metal/oxide (OMO) semi-transparent electrodes and contributes towards a comprehensive understanding of the optoelectronic behavior of LETs.