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Antireflection Patterning of Si for InAsSb Nanowire Infrared Photodetectors

Khalid, Muhammad Rizwan LU (2014) FYSM31 20141
Department of Physics
Abstract
The pattering of an optical surface with physical features like with very low reflectivity and high transmission of IR or visible light can be used e.g. for antireflective windows for solar cells and photodetectors. Here we present results on antireflective patterning of Si for back side illuminated InAsSb nanowire long wavelength IR (8-15 µm) photodetectors. Photolithography and dry etching techniques are used to pattern Si into uniform pillars and by using a Fourier transform infrared spectrometer we measure the transmittance. We use numerical simulations to aid the design of the dimensions of Si pillars. Results from transmittance measurements exhibit diameter dependent peaks that are in good agreement with the numerical simulations.... (More)
The pattering of an optical surface with physical features like with very low reflectivity and high transmission of IR or visible light can be used e.g. for antireflective windows for solar cells and photodetectors. Here we present results on antireflective patterning of Si for back side illuminated InAsSb nanowire long wavelength IR (8-15 µm) photodetectors. Photolithography and dry etching techniques are used to pattern Si into uniform pillars and by using a Fourier transform infrared spectrometer we measure the transmittance. We use numerical simulations to aid the design of the dimensions of Si pillars. Results from transmittance measurements exhibit diameter dependent peaks that are in good agreement with the numerical simulations. The numerical results reveal that the transmission peaks are due to resonant wave guiding modes that enhance the coupling of light into the Si pillars. We have found that with the proper selection of pillar diameter a resonance enhanced transmission peak at specific wavelength can be achieved. We have found that the transmission of IR through bared Si is 53% which is independent of wavelength. Arrays of Si pillars with mean diameter 1.33 μm ± 36 nm show transmission peak at wavelength of 6.2 μm and array of Si pillars having mean diameter 1.42 μm ± 35 nm shifts the transmission peak at wavelength of 7.5 μm. Doughnut shaped Si hollow pillars are also observed as a result of photolithography. The transmission spectrum of Si hollow pillar arrays is also analyzed. (Less)
Please use this url to cite or link to this publication:
author
Khalid, Muhammad Rizwan LU
supervisor
organization
course
FYSM31 20141
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
4432136
date added to LUP
2014-05-08 15:09:05
date last changed
2014-10-22 10:12:23
@misc{4432136,
  abstract     = {{The pattering of an optical surface with physical features like with very low reflectivity and high transmission of IR or visible light can be used e.g. for antireflective windows for solar cells and photodetectors. Here we present results on antireflective patterning of Si for back side illuminated InAsSb nanowire long wavelength IR (8-15 µm) photodetectors. Photolithography and dry etching techniques are used to pattern Si into uniform pillars and by using a Fourier transform infrared spectrometer we measure the transmittance. We use numerical simulations to aid the design of the dimensions of Si pillars. Results from transmittance measurements exhibit diameter dependent peaks that are in good agreement with the numerical simulations. The numerical results reveal that the transmission peaks are due to resonant wave guiding modes that enhance the coupling of light into the Si pillars. We have found that with the proper selection of pillar diameter a resonance enhanced transmission peak at specific wavelength can be achieved. We have found that the transmission of IR through bared Si is 53% which is independent of wavelength. Arrays of Si pillars with mean diameter 1.33 μm ± 36 nm show transmission peak at wavelength of 6.2 μm and array of Si pillars having mean diameter 1.42 μm ± 35 nm shifts the transmission peak at wavelength of 7.5 μm. Doughnut shaped Si hollow pillars are also observed as a result of photolithography. The transmission spectrum of Si hollow pillar arrays is also analyzed.}},
  author       = {{Khalid, Muhammad Rizwan}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Antireflection Patterning of Si for InAsSb Nanowire Infrared Photodetectors}},
  year         = {{2014}},
}