Researchers from several Universities in China developed a self-polarizing RGB device utilizing semipolar microLEDs and perovskite based films aimed at improving backlight applications.
Structure of an LCD based on semipolar blue μLEDs excite anisotropic perovskite NCs as backlight. Image from Opto-Electronic Advances
In standard LCD displays, the backlighting units emits non-polarized light, which then results in an almost 50% light loss as this light has to pass through a polarizer (this is part of the LCD light path). The newly developed high-performance device is designed to emit RGB polarized light which results in higher efficiency and no light-loss dueo to the LCD filter.
Led by Associate Professor Tingzhu Wu, the team engineered a device architecture incorporating blue semipolar microLEDs, which inherently emit polarized light. These LEDs serve as the excitation source for color-conversion layers made from stretched composite films of green and red perovskite nanocrystals. These films exhibit strong polarized emission thanks to their aligned wire structures, further enhanced by encapsulation in a high-dielectric constant material for the red components.
This device design has achieved polarized light emission across the full RGB spectrum with high efficiency and stability, marking a critical advancement in display technology. The green and red perovskite layers maintain their polarization properties under stretch, offering a practical solution for scalable luminescence applications. Furthermore, the device demonstrates a wide color gamut, exceeding standard benchmarks with 137.2% of NTSC and 102.5% of Rec. 2020, alongside impressive Degree of Linear Polarization (DOLP) values across all three colors.
