1-µm Micro-Lens Array on Flip-Chip Light-Emitting Diode
– KH Li, Q Zhang, and HW Choi
Japanese Journal of Applied Physics, vol. 52, 8S, pp. 08JH08 (2013)
The fabrication of hexagonally close-packed micro-lens array on sapphire face of flip-chip bonded LED by nanosphere lithography is demonstrated. Self-assembled silica spheres serve as an etch mask to transfer hemispherical geometry onto the sapphire. The optical and electrical properties are evaluated. Without degrading the current–voltage (I–V) properties, the lensed LED shows an enhancement of 27.8% on light output power, compared with unpatterned LED. The emission characteristic is also investigated by performing finite-difference time-domain simulation, which is found to be consistent with the experimental results.
