Optical performance evaluation of blue tandem top-emitting OLED device

These days, organic light-emitting diodes (OLEDs) have become the mainstream displays in the mobile markets and on the verge of penetrating in the automobile vehicle display sector on large scale. The major problem in such long-lasting display products is the blue device lifetime and efficiency. To overcome these issues, a blue tandem top emission architecture with a strong micro-cavity effect can become the just legitimate candidate. In this study, we have investigated optical performances of fabricated blue tandem top emission OLED (TEOLED) device by comparing the results of two optical simulation methods. Electroluminescent spectra variation, front side efficiency increase ratio, and viewing angle characteristics are compared with the single stack blue TEOLED device results. The calculated front efficiency value by optical simulation for 2 and 3-tandem TEOLED devices were found to be 1.82- and 2.32-times higher than the single stack blue TEOLED device. The experimentally obtained values of 2 and 3-tandem TEOLED devices showed at 1.75 and 2.31, respectively, and are in good agreement with the calculated values. We suggest that the fabricated tandem blue TEOLEDs are suitable for automotive display applications.