68.1: Capacitance‐Voltage Characteristics of Top Emitting Organic Light Emitting Diodes for Mobile Display Application

In this paper, Capacitance-Voltage (CV) measurements as a powerful technique to analyze electric properties of Top emitting OLED (TOLED) devices are introduced. After comparing CV characteristics between inverted TOLED and conventional TOLED with thin metal, it is found that inverted OLED struggles charge injection, especially electron injection. Here Current-Voltage-Luminance (IVL) and CV characteristics are carefully analyzed for single carrier devices and dual carrier devices systematically. Top emitting OLED (TOLED) with thin metal cathode shows more efficient electron injection and higher efficiency than that of inverted OLED, which is attributed to the order of thermal deposition of organic/metal layers.