Enhancing optoelectronic and communication performance of green μ-LEDs using pre-strain layer structures

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Devices

Background:

• Indium Gallium Nitride (InGaN) micro-light-emitting-diodes (μ-LEDs) are crucial for display technologies.
• Lattice mismatch and quantum-confined Stark effect (QCSE) hinder the performance of green μ-LEDs.
• Optimizing crystal quality and strain management is essential for efficient μ-LED operation.

Purpose of the Study:

• To propose and investigate an efficient pre-strained layer structure for InGaN green μ-LED arrays.
• To alleviate strain accumulation and reduce the QCSE in green μ-LEDs.
• To enhance the optoelectronic properties and performance metrics of μ-LED devices.

Main Methods:

• Fabrication of a 2 × 3 InGaN green μ-LED device array (20 μm diameter) using a pre-strained layer structure (pre-layer and pre-well).
• Analysis of the effect of the pre-layer on the lateral lattice constant and strain distribution.
• Characterization of crystal quality and optoelectronic properties under stress modulation.

Main Results:

• The pre-strained layer structure increased the lateral lattice constant, reducing strain accumulation.
• Quantum-confined Stark effect (QCSE) was significantly reduced in the green μ-LEDs.
• External quantum efficiency reached 16.6% and -3 dB modulation reached 411 MHz.
• Performance metrics were 14.8% and 91.2% higher than traditional structures, respectively.

Conclusions:

• The proposed pre-strained layer structure effectively improves the crystal quality and optoelectronic properties of InGaN green μ-LEDs.
• This approach successfully mitigates strain-related issues and enhances device performance.
• The developed μ-LED arrays demonstrate potential for high-efficiency, high-speed display applications.