A novel randomly textured phosphor structure for highly efficient white light-emitting diodes.

Area of Science:

• Solid-state lighting
• Materials science
• Optoelectronics

Background:

• White light-emitting diodes (LEDs) are crucial for energy-efficient lighting.
• Enhancing luminous flux and lumen efficiency in LEDs remains a key research area.
• Current methods for improving LED optical performance can be complex and costly.

Purpose of the Study:

• To demonstrate enhanced luminous flux and lumen efficiency in white LEDs using a randomly textured phosphor structure.
• To present a simple and cost-effective fabrication method for textured phosphor structures.
• To analyze the impact of the textured structure on light extraction and viewing angle.

Main Methods:

• Fabrication of a randomly textured phosphor structure using a simple imprinting technique.
• Comparison of the textured phosphor structure with flat phosphor and half-spherical lens structures.
• Measurement of luminous flux, lumen efficiency, and viewing angle at a driving current of 120 mA.

Main Results:

• The textured phosphor structure increased luminous flux by 5.4% compared to flat phosphor structures.
• Luminous flux was enhanced by 2.5% compared to half-spherical lens structures.
• The textured structure resulted in a larger full width at half maximum viewing angle (87°) compared to reference LEDs.
• Enhanced utilization efficiency of blue light was observed due to surface scattering and phosphor particle effects.

Conclusions:

• A randomly textured phosphor structure offers a viable and efficient method for improving white LED performance.
• The simple imprinting technique provides a cost-effective alternative to complex fabrication processes.
• The enhanced light extraction and wider viewing angle contribute to superior LED performance.