Nanostructured broadband antireflection coatings on AlInP fabricated by nanoimprint lithography Advisor : P. C. Yu Speaker : G. S. Hong Optoelectronics Research Centre, Tampere University of Technology, Korkeakoulunkatu 3, 33720, Tampere, P.O. Box 692, 33101 Tampere, Finland
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Advisor : P. C. Yu Speaker : G. S. Hong Optoelectronics Research Centre, Tampere University of Technology, Korkeakoulunkatu 3, 33720, Tampere, P.O. Box.
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Nanostructured broadband antireflection coatings on AlInP fabricated by nanoimprint lithography
Advisor : P. C. YuSpeaker : G. S. Hong
Optoelectronics Research Centre, Tampere University of Technology, Korkeakoulunkatu 3, 33720, Tampere, P.O. Box 692, 33101 Tampere, Finland
Outline
Introduction Experiment Results Conclusion
Moth-eye AR structures.
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.
Introduction
moth’s head moth-eye
Fabrication
The yield is approximately 95% over an 4 cm^2 consisted of 4.4x1e9 nanocones.
Arrays of metallic nanocones fabricated by UV-nanoimprint lithographyJuha M. Kontio *, Janne Simonen, Juha Tommila, Markus PessaOptoelectronics Research Centre, Tampere University of Technology, P.O. Box 692, FIN-33101, Tampere, Finland
Fabrication steps (1)
Laser interference lithography (LIL) UV - NIL
http://0rz.tw/mev4Chttp://0rz.tw/IAGJV
Fabrication steps (2)
PMMA Si
GeUV-NIL resist
Structure in Simulation
A :30/170/370 nm (top diameter/base diameter/height) B : 50/220/370 nmC : 80/300/440 nmReference : 1 um AlInP
Simulation & Measurement
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.
Arithmetic average reflectivities
Reflection of the laserGaAs’PL
Absorption of the laser and the PL in the AlInP layer
PL intensities
Conclusion
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.