1,137 reputation
411
bio website daniel.farrell.name
location Tokyo, Japan
age
visits member for 4 years, 4 months
seen 7 hours ago

I know how to use the grey square -- do you?


May
10
comment How do the Fermi level, HOMO and LUMO change with doping?
If you provide some references that mention constant fermi-level we can probably tease this apart.
May
9
comment How do the Fermi level, HOMO and LUMO change with doping?
Why is the Fermi level constant with doping? This is the level of 50% occupancy; this should change with doping.
May
8
comment Steady State Solution for Carrier Concentration of Intrinsic Silicon in an Electric Field
This is pretty difficult. You also need to solve the Poisson equation to provide $E(x)$. The standard approach is to user the Boltzmann approximation and change variables to from carrier densities to quasi-Fermi-levels. Then you need to discretise the equations (FD, FVM or FEM) and include some form of exponential fitting to keep the equations stable when the Peclet's number is large. Then for accurate solutions some form of adaptive mesh refinement should be used. All in all a very tricky problem! Take a look at the pn-junction solvers on nanohub.org they might get you started.
May
5
answered Bimolecular recombination in few words
May
4
comment Diodes in AC current
If you move it very quickly you will still be able to see the on-off cycle at 60Hz as streaks.
May
4
comment Is refraction of light a thermodynamic process?
Total internal reflection has a thermodynamic/statistical interpretation: is a mismatch between the plentiful internal optical modes and the fewer modes available in the less optically dense material across the interface. I have not thought about a similar analogue for refraction but I imagine the same mental model could be used to describe this process.
May
4
answered What are the purposes of slits inside a spectrometer (Czerny-Turner)?
Apr
29
comment How to convert the molar attenuation coefficient, ie. molar absorptivity, to heat capacity?
Nice answer! But does not include how to convert from spectroscopy measurements to heat capacity which was OP's questions.
Apr
23
comment When they say the universe was the size of a baseball about a billion billion billion billionth of a second
It means the whole universe. This is important cosmological point because inflation solves the horizon problem (the near uniform temperature distribution of the night sky).
Apr
22
answered Lens to optimize field of view through a tube
Apr
19
comment Optical system for cloning an image of a light source?
This already does what you want (3 criteria in your question). I don't understand what you are talking about!
Apr
19
comment Optical system for cloning an image of a light source?
I don't think you understand. Mirror 2 and 3 reflect light towards both eyes!
Apr
19
answered Optical system for cloning an image of a light source?
Apr
19
comment Optical system for cloning an image of a light source?
Actually if you need to preserve the divergence then it's easier with a second mirror.
Apr
19
comment Optical system for cloning an image of a light source?
Seriously you can do this with just the two components I said. Think about it. I can't draw a diagram right now.
Apr
19
comment Optical system for cloning an image of a light source?
50:50 beam splitter and a 45 degrees mirror will do it.
Apr
15
comment How does a photon drive out the electrons in a solar cell?
This is complicated. You will have to understand band structure of semiconductors, and then semiconductor device physics to get a full answer. However, you can also describe the operation of a solar cell purely with thermodynamic, but as you are asking about the actual mechanics I don't think this is what you want. I would suggest reading Jenny Nelson's of Peter Würfel's solar cell books. It's too much to cover in a single answer.
Apr
13
comment By what maximum amount can we concentrate sunlight?
The factor of two is cancelled when performing the angular integrations.
Apr
13
revised By what maximum amount can we concentrate sunlight?
Showing working.
Apr
13
revised By what maximum amount can we concentrate sunlight?
Added the photovoltaics tag