Highly Efficient Red, Green, and Blue Inverted Top-Emitting Organic Light-Emitting Diodes with Microstructured TiN Substrate

The morphological and optical properties of microstructured silicon substrates (M-Si) and inverted top-emitting organic light-emitting diodes (ITOLEDs) based on the M-Si/Ti/TiN/Al composite electrodes are studied. The developed M-Si/Ti/TiN/Al composite electrodes function well in improving the performance of red, green, and blue ITOLED. The Al thin film deposited on TiN silicon substrate could significantly improve the reflectivity of the electrode, and the microstructured substrate could further increase the reflective path for lights inside OLEDs. Meanwhile, by adopting a light output-coupling layer on top of the device and using the localized surface plasmon resonance effect of the top-emitting structure, the angle-dependent effect of ITOLEDs based on the composite electrodes is reduced. Through employing the M-Si/Ti/TiN/Al composite electrodes, all the red, green, and blue OLEDs achieve an improved performance, and the red OLED shows the best performance enhancement, with the luminance of 26 247 cd m-2, maximum current efficient of 30.7 cd A-1, and maximum external quantum efficiency of 17.4%. This provides a new strategy to achieve highly efficient ITOLEDs. This work adopts microstructured silicon substrates (M-Si) and light coupling layer to obtain efficient inverted top-emitting organic light-emitting diodes (OLED). Through employing the M-Si/Ti/TiN/Al composite electrodes, the red, green, and blue OLEDs achieve improved performance. The red OLED shows the best performance, with the luminance of 26247 cd/m2, current efficient of 30.7 cd/A, and maximum external quantum efficiency of 17.4%.image (c) 2024 WILEY-VCH GmbH