Semi conductors for chemistry students

Richard Pilkington came to the lesson today to talk about the semi-conductor industry and how it can apply to chemistry/biochemistry students like our selves. He started by saying that transistors were first created in 1947 by William Shockley, John Bardeen and Walter Brattain in America.

A transistor is made of an oxidative layer on the top of an n-type silicon (elements such as phosphorous) and contained inside a p - type silicon (elements such as boron). Silicon is a semi-conductor that which means that it is a material element that acts in the middle ground of plastics and metals in terms of its ability to conduct electricity. The N- type provides free electrons that can carry electrical currents and encourage the flow out of the transistor whereas the P-type has fewer free electrons that encourages electrons to flow into it. When a current flows into a transistor this method amplifies the current that is passing through it.

             After this we were told of Moors law which states that “transistor density on integrated boards doubles every two years” this means that the technology gets smaller and better every two years and he provided us with electrical equipment from 30 years ago that had 16 transistors which is very minor compared to today’s levels such as 256 billion transistors (wow!!!) that are used in iPod’s, this shows how essential the progression of this technology is, it has become some integrated into our everyday lives without realising it. Silicon is the second most abundant element on earth after oxygen and makes 25% of the earth’s crust and can be used in this way in many areas. One of the most prominent technologies that people will hopefully benefit from is in the use of solar panels. Silicon is ideal for this because its abundance makes it cheap and it has a very long life span.

The silicon substrate is made by SiO₂ + C = Si + CO₂, this is done in a 1900 c degree furnace which gives metallurgical grade Si. The Si then goes through purification process of Si + 3HCL = SiHCL₃ + H₂. In the final stage the silicon is refined to reduce impurities through SIHCL₃ + H₂ = Si + 3HCL. He showed us a sample of the refined silicon and it was interesting to handle this because I take for granted such materials but holding such a heavy amount was interesting because I could feel the weight that I did not expect and it was as reflective as a mirror. At the end of his presentation someone asked about how this area could apply to biochemistry and he stated that because our course covers subjects like genetics and physiology we would be in great demand because this area of technology is looking to move into physiology and medicine and biochemists will be needed to bridge the gap of knowledge.

I found this area extremely interesting because it was exploring the engineering side of science and it was good to see how chemistry applies to engineering instead of the biological side of it. I would have liked to know who are these people who are in need of biochemists in this industry, it’s all good saying that people will want my knowledge and skills but I would like to know who these companies are and how I can apply for work with them.