Out-coupling Efficiency of PVOLED Improved by Distributed Bragg Reflector

Photovoltaic-device-integrated Organic Light Emitting Diode (PVOLED) is a green technology concept that both improves the ambient contrast ratio (A-CR) and recycles the energy by the photovoltaic device. However, due to the emitting light absorbed by the photovoltaic device, the out-coupling efficiency of OLED drops a lot. We will introduce the OLED, photovoltaic device, and the history of integrated device. We use the finite-difference time-domain (FDTD) method to get the out-coupling efficiency, and the efficiency of photovoltaic device is calculated by rigorous coupled-wave analysis (RCWA), continuity equation and Poisson''s equation. In order to enhance the out-coupling efficiency of PVOLED, we introduce an optical filter in the structure, and the reflection spectrum of the filter is designed to be corresponding to the OLED emitting spectrum. In this study, we use the distributed Bragg reflector (DBR) as the optical filter, and discuss the overall performance among out-coupling efficiency, efficiency of photovoltaic device and A-CR with different DBRs. By introducing the concept of Fabry–Pérot interferometer, we can further understand the DBR structure. By choosing the materials of DBRs with considering the effect of Fabry–Pérot interferometer, the device performs better.