1. Could you explain the significance of your article to the non-specialist? 

The functional roles of all the active components/materials in the multilayer OLED devices need to be optimized in order to achieve highly efficient performance for large area full-color displays, such as for TV applications. For long life-time usages, the materials also need to be highly thermally and morphologically stable. In addition to the light emitting materials, the hole-blocking material is often used in between the emitting layer and the electron-transport layer in the multilayer OLEDs to enhance/ maintain the good device performance and efficiency as well as the long life-time of OLED devices. As a result, the morphological stability and hole-blocking/electron transporting property of a hole-blocking material is directly related to the stability and performance of the OLED devices.

2. What has motivated you to conduct this work?

Currently, good hole-blocking materials with highly stable morphology are still very limited. One of our ongoing efforts is to develop highly efficient as well as thermally and morphologically stable hole-blocking/electron transporting materials for high-performance multilayer OLED devices.

3. Where do you see this work developing in the future? 

Based on our results, the use of fluorine-containing molecules to achieve hole-blocking properties appears promising for further development. It is anticipated that more activities/interests will be working toward that direction.

4. Are there any particular challenges facing future research in this area? 

As more and more highly efficient emitting materials have been developed, there is a great need of other efficient and stable active materials such as hole-blocking materials to render the realization of the highly efficient light emitting performance. Development of advanced materials possessing both good hole-blocking/electron transporting properties in combination with high morphological stability (T_g greater than 130 °C) is challenging as these materials are still very limited.