PeLED Lights 3D Display, Secure Comms Revolution

Abstract

Chiral halide perovskites have emerged as promising materials for spin-optoelectronic devices owing to their ability to emit circularly polarized light (CPL) through spin-selective processes. However, the realization of high dissymmetry factors in perovskite-based circularly polarized light-emitting diodes (CP-LEDs) remains challenging. Herein, CP-LEDs based on quasi-2D perovskites incorporating two types of chiral materials are demonstrated, which achieve high circular polarization. R-/S-methylbenzylammonium iodide (MBAI) is employed to construct quasi-2D perovskite structures and R-/S-1,1′-binaphthyl-2,2′-diyl hydrogen phosphate (BHP) to enhance chiral distortion. Enhanced CPL emission with higher dissymmetry factors is observed due to a synergistic effect of the matching handedness of MBAI and BHP. The enhanced circular dichroism in the absorption band of the n = 1 2D perovskite reveals the presence of chiral distortion, which leads to strong CPL emission. The results of density functional theory calculations and micro-strain analysis are further supported by the observed chiral distortion of the inorganic perovskite lattice. Moreover, BHP effectively passivated the perovskite defects through its phosphate groups. The resulting CP-LEDs exhibit an enhanced electroluminescence dissymmetry factor of 7.5 × 10−2 and an external quantum efficiency of 6.9%, demonstrating their potential for practical application in chiro-optoelectronics.

3D movies often appear dimmer than regular films because of polarizing filters that block certain light components to create the 3D effect. Thanks to …. created a perovskite LED (PeLED) that emits circularly polarized light inherently, eliminating the need for filters. This breakthrough promises brighter 3D displays and more secure data transmission.

Led by Professors Myoung Hoon Song and Seung Geol Lee from the Department of Materials Science and Engineering, the team integrated specially designed chiral molecules within the perovskite layer, enabling the PeLED to produce high-purity circularly polarized light (CPL) on its own.

Circular polarization involves light rotating clockwise or counterclockwise as it travels. Traditional methods generate CPL through filters, which reduce brightness. These new PeLEDs emit the desired polarization intrinsically, preserving brightness and efficiency.

Figure 1. Device schematic, showing the structure with R-/S-MBA and R-/S-BHP molecules, which induce lattice distortion in the n = 1 layer, enhancing spin funneling and CPL emission.

The key innovation was combining two complementary chiral molecules: methylbenzylammonium iodide (MBAI) and 1,1′-binaphthyl-2,2′-diyl hydrogen phosphate (BHP). While single chiral molecules often cause inconsistent twisting and lower polarization, mixing MBAI and BHP created a synergistic effect: MBAI guides the overall twist, and BHP reduces defects, improving stability.

Their theoretical calculations confirmed that this combination effectively controls both the direction and intensity of CPL emission. Experimentally, device performance improved significantly: the dissymmetry factor (g_CP-EL) reached 7.5×10⁻²-about three times higher than single-molecule devices. External quantum efficiency (EQE) increased from 1.28% to 6.9%, and brightness nearly doubled from 742 cd/m² to 1,753 cd/m².

These advancements open new possibilities for applications requiring precise control of light's polarization, such as secure quantum communication and high-end displays. Higher polarization purity enhances data encoding accuracy, making these PeLEDs promising for quantum encryption and secure channels.

Professor Song noted, "PeLEDs already outperform OLEDs in manufacturing cost and efficiency for circularly polarized light. Our technology not only paves the way for brighter, filter-free displays but also positions us to lead in emerging fields like quantum security and high-value communications."

Supported by the National Research Foundation of Korea (NRF), the findings of this research have been published in the online version of Advanced Functional Materials on December 3, 2025.

Journal Reference

Yong-Jun Choi, Hengquan Guo, Jongmin Han, et al., "Structural Distortion-Driven Chirality Transfer and Circularly Polarized Light Emission in Quasi-2D Perovskites Based Light-Emitting Diodes," Adv. Funct. Mater., (2025).