Optimum Design Configuration of Thin-Film Transistors and Quantum-Dot Light-Emitting Diodes for Active-Matrix Displays

Active matrix (AM) quantum-dot light-emitting diodes (QLEDs) driven by thin-film transistors (TFTs) have attracted significant attention for use in next-generation displays. Several challenges remain for the realisation of AM-QLEDs, such as device design, fabrication process, and integration between QLEDs and TFTs, depending on their device structures and configurations. Herein, efficient and stable AM-QLEDs are demonstrated using conventional and inverted structured QLEDs (C- and I-QLEDs, respectively) combined with facile type-convertible (p- and n-type) single-walled carbon nanotube (SWNT)-based TFTs. Based on the four possible configurations of the QLED-TFT subpixel, the performance of the SWNT TFT-driven QLEDs and the fabrication process to determine the ideal configuration are compared, taking advantage of each structure for AM-QLEDs. The QLEDs and TFTs are also optimized to maximise the performance of the AM-QLEDs-the inner shell composition of quantum dots and carrier type of TFTs-resulting in a maximum external quantum efficiency and operational lifetime (at an initial luminance of 100 cd m2) of 21.2% and 38 100 000 h for the C-QLED, and 19.1% and 133100000 h for the I-QLED, respectively. Finally, a 5x5 AM-QLED display array controlled using SWNT TFTs is successfully demonstrated. This study is expected to contribute to the development of advanced AM-QLED displays. A comparative study on four practical combinations of QLED-TFT integrated devices is herein presented for efficient and stable AM-QLED display. Taking into consideration device structure and carrier type between QLED and TFT, AM-QLED display is compared and analyzed to find out ideal combinations, and thus a 5x5 AM-QLED display array controlled using SWNT TFTs is successfully demonstrated.image

Automated summary

In this study, efficient and stable AM-QLEDs for next-generation displays are demonstrated by comparing different configurations of QLEDs and TFTs. A 5x5 AM-QLED display array controlled using SWNT TFTs is successfully demonstrated, contributing to the development of advanced AM-QLED displays.