Thursday, 28 May 2009
Wednesday, 22 April 2009
The day the science nearly worked
Today something quite remarkable happened. Some science, not original science I admit but something replicated from another paper, actually worked in almost the way that it was supposed to. A mere two hours of (not at all) gentle illumination under a UV laser while sitting in a crude electrochemical cell featuring potassium hydroxide and my little semiconductor wafer was etched away to reveal the precious sapphire lurking beneath.
So in this picture we see a strange parallel wall structure which somehow survived the etching. Most likely it was a scratch on the surface which caused the Gallium Nitride (the semiconductor in question) to stand up to the malevolent potassium and hydroxide ions. The point is that:
a) It looks pretty
b) The GaN itself seems to be made from two distinct layers (we're guessing it is to do with some "dopants" getting involved when the wafer was grown)
c) It's a minor success but it's the first success that I've had in eighteen months of PhD
d) That broken wasteland at the bottom of the double wall is sapphire. As in the gemstone.
e) The image was taken with a FIB (essentially you nail Gallium ions at the surface and look for the electrons which come flying off)
So in this picture we see a strange parallel wall structure which somehow survived the etching. Most likely it was a scratch on the surface which caused the Gallium Nitride (the semiconductor in question) to stand up to the malevolent potassium and hydroxide ions. The point is that:
a) It looks pretty
b) The GaN itself seems to be made from two distinct layers (we're guessing it is to do with some "dopants" getting involved when the wafer was grown)
c) It's a minor success but it's the first success that I've had in eighteen months of PhD
d) That broken wasteland at the bottom of the double wall is sapphire. As in the gemstone.
e) The image was taken with a FIB (essentially you nail Gallium ions at the surface and look for the electrons which come flying off)
Saturday, 11 April 2009
Wednesday, 8 April 2009
Friday, 13 March 2009
Thursday, 12 March 2009
My new favourite science machine

What you see there was once a boring glass slide. With the home magic of glue and some random little bits of metal though it was transformed! Well the transformation actually came from the blinging process of depositing a hundred nanometres of west coast purity silver on to it. Next up for the evaporator: gold and a shoe!
Sunday, 1 March 2009
Monday, 2 February 2009
The roof is full of snow holes

Of course it would appear that my phone has the special ability to dynamically remove snowflakes from a shot. So all we have here is a picture of Cabot Circus, the exciting new centre of Bristol, when really I wanted to demonstrate what happens when snow falls on a series of overlapping domes with small gaps between them.
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