An overview about the use of electrical doping of charge carrier transport layers in OLEDs and further organic electronic applications

Electrical doping of organic layers is now a well established method for building highly efficient and long living OLEDs. A unique class of OLED devices called PIN-OLEDs based on redox doping technology is emerging as one key technology for OLED applications. These devices exhibit high power efficiency and long life time, which are critical parameters for commercial success. Moreover, PIN OLEDs offer high degree of freedom in choosing layer structures for optimizing the device performance for specific lighting and display applications. For example, optimizing color and power efficiency of OLEDs can be easily achieved without compromising the device operating voltage. It is worth to mention that PIN OLEDS, especially the red emitting PIN OLEDs, exhibit record breaking half life time of more than one million hours with the starting device brightness of 1000 cd/m(2). The doping technology also offers benefits to other organic electronic devices such as OTFTs and photovoltaic devices. This paper briefly discusses the improvements made on the OLED device performance such as power efficiency and lifetime using doped transport layers. Few examples of device optimization using doped layers are presented in detail. In addition, a brief discussion on performance of doped transport layers in photovoltaics is also presented

Outcoupling technologies : concepts, simulation, and implementation

Optimizing light out-coupling in organic light-emitting diodes (OLEDs) is at the heart of the development and commercialization of OLEDs for general lighting and display applications as it impacts directly the achievable luminous emission (lm/m2), luminous efficacy (lm/W), and even the lifetime. The improvement of light out-coupling requires having simulation tools at hand to efficiently simulate such OLEDs that include light out-coupling enhancement structures. In this chapter we will first describe the main concepts employed today to improve light out-coupling without employing scattering, and then we will introduce how light scattering-based out-coupling tricks can help to maximize the emitted luminance of the device. On this occasion, we will detail a modeling workflow that allows to accurately simulate OLEDs including scattering structures. In this part, we will make use of simulations in order to optimize the device efficiency. From the simulations it becomes evident that the OLED thin film stack properties and the light scattering structures of the substrate both influence the overall performance and thus have to be jointly optimized