Ameliorating Uniformity and Color Conversion Efficiency in Quantum Dot-Based Micro-LED Displays through Blue-UV
Tzu-Yi Lee1, Wen-Chien Miao2,3, Yu-Ying Hung1
1Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
Nanomaterials (Basel, Switzerland)
|July 29, 2023
Summary
This study introduces a novel hybrid micro light-emitting diode (μ-LED) design using quantum dots (QDs) and titanium dioxide (TiO2) for efficient full-color displays. The optimized structure significantly improves color conversion efficiency and display performance.
Area of Science:
- Materials Science
- Optoelectronics
- Display Technology
Background:
- Quantum dot (QD)-based micro light-emitting diodes (μ-LEDs) are crucial for advanced full-color displays.
- Achieving high color-conversion efficiency (CCE) and uniformity in QD μ-LEDs remains a challenge.
Purpose of the Study:
- To propose and validate a novel hybrid μ-LED structure combining blue and UV-based quantum well (QW)-intermixing for enhanced CCE.
- To systematically investigate the effects of QD and TiO2 concentrations and thickness on photoluminescence quantum yield (PLQY) through simulation.
- To develop a high-efficiency color-conversion layer (CCL) for improved display performance and reduced fabrication costs.
Main Methods:
- Optical simulations were employed to optimize QD and TiO2 concentrations and CCL thickness for maximum PLQY.
- High-efficiency CCLs were fabricated using the simulation-derived parameters.
- Titanium dioxide (TiO2) scattering particles were incorporated into the CCL to improve QD dispersion and light absorption.
- A passivation protection layer was applied using low-temperature atomic layer deposition (ALD) for enhanced device reliability.
- A modified distributed Bragg reflector (DBR) was integrated to minimize light leakage.
Main Results:
- Simulations guided the fabrication of optimized CCLs, reducing time and material costs.
- The inclusion of TiO2 scattering particles improved QD dispersion, reduced aggregation, enhanced light absorption, and increased illumination uniformity.
- The hybrid μ-LED design achieved impressive CCE values of 96.25% for red and 92.91% for green CCLs.
- The developed display system expanded the color gamut to 128.2% NTSC and 95.8% Rec. 2020.
- A passivation layer using ALD enhanced the reliability of the CCL.
Conclusions:
- The proposed hybrid μ-LED structure with a QD/TiO2 CCL offers a viable pathway for high-performance, efficient full-color displays.
- The integration of optical simulation and experimental validation accelerates the optimization of μ-LED parameters.
- This approach significantly enhances CCE, uniformity, and color gamut, paving the way for next-generation display technologies.
