Enhancement of Light Extraction Efficiency for InGaN/GaN Light-Emitting Diodes Using Silver Nanoparticle Embedded ZnO...

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Indium gallium nitride/gallium nitride (InGaN/GaN) light-emitting diodes (LEDs) are crucial for solid-state lighting.
• Improving light extraction efficiency (LEE) is essential for enhancing LED performance.
• Existing methods for LEE enhancement often involve complex fabrication processes.

Purpose of the Study:

• To develop a cost-effective method for improving the LEE of InGaN/GaN LEDs.
• To investigate the effect of silver nanoparticle (Ag NP) embedded zinc oxide (ZnO) thin films on LED performance.
• To optimize the deposition parameters for enhanced light output.

Main Methods:

• Fabrication of a liquid-phase-deposited silver nanoparticle embedded ZnO (LPD-Ag NP/ZnO) thin film at room temperature.
• Utilizing a treatment solution comprising ZnO-powder-saturated HCl and silver nitrate (AgNO₃) aqueous solution.
• Characterization of the thin film's surface texture (RMS roughness) and optical properties (LSP resonance/extinction wavelength) as a function of AgNO₃ concentration.

Main Results:

• The LPD-Ag NP/ZnO thin film significantly enhances the LEE of InGaN/GaN LEDs.
• Enhanced LEE is attributed to the combined effects of surface texturing and localized surface plasmon (LSP) coupling.
• An optimal AgNO₃ concentration of 0.05 M resulted in a 1.52-fold increase in light output intensity compared to conventional LEDs at 20 mA.

Conclusions:

• The LPD-Ag NP/ZnO thin film is an effective window layer for improving InGaN/GaN LED performance.
• The concentration of AgNO₃ is a critical parameter for controlling Ag NP size, content, and surface morphology, thereby optimizing LEE.
• This room-temperature deposition method offers a promising approach for fabricating high-efficiency LEDs.