Patent ID: 10804431

Abstract:
Current-injecting nanorod LEDs are demonstrated to emit linear polarized light that is detected from the backside of the sample. The polarization ratio of the electroluminescence reaches 71% when the length of the minor axis is as small as 150 nm. Electromagnetic simulation confirms the occurrence of the polarization selectivity especially when the length of the minor axis is down to 150 nm. The destructive interference between the light directly from light source and the reflected light by the top metal interface is the origin of the selectivity. Emission with the polarization perpendicular to the nanorods is extracted out of the nanorods and the remaining light with the other polarization transmits to the substrate. The linearly polarized light can be also detected from the front side of the sample if the conductive pad is transparent. The simulation also suggests that it is possible to obtain circularly or elliptically polarized light by tuning the height of the nanorods. These observed phenomena could also apply to fin-shaped nanowall LED. The results in this study will be beneficial for applications that required linearly or circularly polarized light especially for devices that are not suitable to use an external polarizer.