Something I didn't notice during your presentation: On slide 15, you have plots comparing the measured value against the paper equation and the Shockley equation.
We see that both agree at higher temperature and higher bias?
Having a look at the behaviour of the current density for zero bias, this differs by about 4 orders of magnitude. Why? Also, I would have suspect zero current for no potential difference. Is bias different to this or was there some other effect?
Also, why are there fewer temperatures plotted for the Shockley equation?
2. I shall answer this paragraph in reverse order. Bias is just potential difference. The current at zero bias comes from the migration of thermally stimulated charge carriers, which form a "depletion layer" somewhat similar to that in inorganic semiconductors. This is why it varies with temperature.
3. I presume that there are fewer temperatures plotted for the shockley equation for two reasons. Firstly, because of the deviation from the data, if all of the temperatures were plotted, the plot could look quite confusing (just like this sentence :P). Secondly, the Shockley equation has been around for a while (published in 1950 http://en.wikipedia.org/wiki/William_Shockley). I presume that they felt less of a need to demonstrate this equation.
Something I didn't notice during your presentation:
ReplyDeleteOn slide 15, you have plots comparing the measured value against the paper equation and the Shockley equation.
We see that both agree at higher temperature and higher bias?
Having a look at the behaviour of the current density for zero bias, this differs by about 4 orders of magnitude. Why?
Also, I would have suspect zero current for no potential difference. Is bias different to this or was there some other effect?
Also, why are there fewer temperatures plotted for the Shockley equation?
1. yes
ReplyDelete2. I shall answer this paragraph in reverse order. Bias is just potential difference. The current at zero bias comes from the migration of thermally stimulated charge carriers, which form a "depletion layer" somewhat similar to that in inorganic semiconductors. This is why it varies with temperature.
3. I presume that there are fewer temperatures plotted for the shockley equation for two reasons. Firstly, because of the deviation from the data, if all of the temperatures were plotted, the plot could look quite confusing (just like this sentence :P). Secondly, the Shockley equation has been around for a while (published in 1950 http://en.wikipedia.org/wiki/William_Shockley). I presume that they felt less of a need to demonstrate this equation.
Thanks for the good questions ^_^