Nanostructured broadband antireflection coatings on AlInP

Report
Optoelectronics Research Centre, Tampere University of Technology, Korkeakoulunkatu 3,
33720, Tampere, P.O. Box 692, 33101 Tampere, Finland
Advisor : P. C. Yu
Speaker : G. S. Hong
Introduction
 Experiment
 Results
 Conclusion

Introduction

Moth-eye AR structures.
moth’s head
moth-eye

AlInP has a very large band gap (1.3~2.4eV) and high transparency.

This letter demonstrates moth-eye antireflection coatings fabricated by
UV-nanoimprint lithography (NIL) on AlInP/GaAs structure.
The yield is approximately 95% over an 4 cm^2 consisted of 4.4x1e9 nanocones.
Arrays of metallic nanocones fabricated by UV-nanoimprint lithography
Juha M. Kontio *, Janne Simonen, Juha Tommila, Markus Pessa
Optoelectronics Research Centre, Tampere University of Technology, P.O. Box 692, FIN-33101, Tampere,
Finland
Fabrication steps (1)
Laser interference lithography (LIL)
http://0rz.tw/IAGJV
UV - NIL
http://0rz.tw/mev4C
Fabrication steps (2)
UV-NIL
resist
PMMA
Ge
Si
Simulation & Measurement
A :30/170/370 nm (top diameter/base diameter/height)
B : 50/220/370 nm
C : 80/300/440 nm
Reference : 1 um AlInP
Arithmetic average reflectivities
The simulated values are lower than the measured ones partly due to :
 The imperfect model of the dielectric function.
 The roughness of the etched surfaces.
 The silver mirror used as a reference in the measurements.
PL intensities
Reflection of the laser
GaAs’PL
Absorption of the
laser and the PL in
the AlInP layer

An average reflectivity of 2.7% was achieved for
wide spectral range 450–1650 nm.

Using PL measurements, we have shown that the
surface recombination and patterning induced losses
are low.
Thanks for your attention !

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