Material and device engineering for efficient quantum rod light emitting diodes

The aligned quantum rods emit polarized light that could improve the efficiency of the LCD backlights. Semiconductor quantum rods (QRs), due to their unique shape-dependent emission properties, have been a centre of attraction for the last decade [1-13]. These materials not only exhibit the quantum confinement effect due to their size, but also show polarized photoluminescence properties. In this talk, we will discuss the High-quality alignment of the QRs showing a high polarization ratio for the PL. We developed photoaligned quantum rod enhancement films (QREF) containing red and green QRs for their application in LCD backlights. The QRLEDs, theoretically, can achieve an external quantum efficiency (EQE) of more than 40 %. However, there are numerous hurdles to attaining this high EQE, including packing density, leakage current, innovative device engineering, QR material structure, and ligands. In this talk, I will discuss some of these issues and our recent findings for the QRLEDs ((see Fig. 1 (l-p)). We will also share some of the recent results. We have achieved a record-high EQE of 32 % for red, 24 % for green, and 9 % for blue QRLEDs.