Self-polarized RGB device realized by semipolar micro-LEDs and perovskite-in-polymer films for backlight applications

Abstract

In backlighting systems for liquid crystal displays, conventional red, green, and blue (RGB) light sources that lack polarization properties can result in a significant optical loss of up to 50% when passing through a polarizer. To address this inefficiency and optimize energy utilization, this study presents a high-performance device designed for RGB polarized emissions. The device employs an array of semipolar blue µLEDs with inherent polarization capabilities, coupled with mechanically stretched films of green-emitting CsPbBr3 nanorods and red-emitting CsPbI3-Cs4PbI6 hybrid nanocrystals. The CsPbBr3 nanorods in the polymer film offer intrinsic polarization emission, while the aligned-wire structures formed by the stable CsPbI3-Cs4PbI6 hybrid nanocrystals contribute to substantial anisotropic emissions, due to their high dielectric constant. The resulting device achieved RGB polarization degrees of 0.26, 0.48, and 0.38, respectively, and exhibited a broad color gamut, reaching 137.2% of the NTSC standard and 102.5% of the Rec. 2020 standard. When compared to a device utilizing c-plane LEDs for excitation, the current approach increased the intensity of light transmitted through the polarizer by 73.6%. This novel fabrication approach for polarized devices containing RGB components holds considerable promise for advancing next-generation display technologies.

Keywords

• halide perovskite
• light-emitting-diodes
• polarized emission
• nanocrystals
• stability