Ideally Ordered Anodic Porous Alumina Mask

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Ideally Ordered Anodic Porous Alumina Mask
Acknowledgements Swee Hoe Lim Daniel Derkaks
Cal-(It)2 UCSD
Shaw, Jonathan Advisor Edward T. Yu

• Motivation
• Use porous alumina templates as masks to
• assemble nanoparticles. The metallic
  nanoparticles
• has surface plasmon resonances that can
  enhance
• large electromagnetic field at a certain
  resonance
• wavelength.
• Enhance in the optical absorption of
  semiconductor
• by depositing nanorods on the surface through
  the
• excitation of surface plasmon resonances.
  This
• result may improve the performances of devices
  
• such as photodectors.

Preparation steps for implementing highly ordered
array of nanowires

• Problem
• Need to know the conditions of anodization
• that control various parameters of the film.
• Break through the alumina barrier to enable
• electroplating nanparticles. Need to
  determine
• the thickness of the barrier layer.

Pore Depth, 20um

• Future Goals
• Increase the efficiency of solar cells.
• Create more efficient optical sensors
• in the infrared range.

SEM Result

• Solution
• The inter-pore distance and pore diameter
• are directly proportional to the anodization
• voltage setting.
• Two methods to widen the pore diameter.
• One method is using chemical etching
• using phosphoric acid after the second
• anodization. Another plausible method is
• through Ion Milling.

Nano Pores, 21V, 15 degrees
Nano Pores, 60V, 15degrees