Fully Solution Processed Organic Light-emitting Electrochemical Cells (OLEC) with ZnO Interlayer for Lab-on-Chip Applications

Abstract

Microfluidic lab-on-a-chip devices can be used for chemical and biological analyses such as DNA tests or environmental monitoring. In order to make a monolithic and cost-efficient/disposable sensing device, direct integration of excitation light source for fluorescent sensing is often required. A manufacturing process for fully solution-processed blue organic light-emitting electrochemical cells (OLECs) is presented, which consist of pre-patterned ITO, spin-coated ZnO buffer layer and blue light-emitting polymer plus dopants and an inkjet-printed PEDOT:PSS transparent top anode. Furthermore, the fully transparent blue OLEC is able to emit > 2000 cd/m2 light under pulsed driving mode, which fulfils requirements for simple fluorescent on-chip sensing applications. Furthermore, ITO electrodes can be replace by PEDOT:PSS transparent electrodes when a ZnO interlayer is solution processed on top, which enable the mask-free and fully solution processing integration on chips.