Timeline for 3 Ways of treating an external Potential in a PN-Junction
Current License: CC BY-SA 3.0
6 events
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| Oct 6, 2016 at 23:26 | comment | added | freecharly | The term "chemical potential" you used has to be understood in the sense of "total chemical potential" which is synonymous to "electrochemical potential" which includes electric potential. | |
| Oct 6, 2016 at 23:24 | comment | added | freecharly | Also the chemical potential + the electrical potential, which is called electrochemical potential, is not constant in a a pn-junction with an applied voltage. It is constant in a device in equilibrium without an applied voltage. In equilibrium there is no flow of energy into the device, which you would have when you have a current I and an applied voltage V. This would give you a power P=V·I that is dissipated and thus supplied to the device. | |
| Oct 6, 2016 at 23:13 | comment | added | Quantumwhisp | I never said the quasi-chemical potential has to be constant, but instead it + the potential together should be constant. That is the way a potential bends the chemical potential in the equilibrium situation. Why does equilibrium mean that there are no currents? To me equilibrium just means that the distribution doesn't change. The term equilibrium may be not sharply definded thouth, since we're looking at many statistic systems linked together here, not just one. | |
| Oct 6, 2016 at 23:00 | comment | added | freecharly | No, in thermodynamic equilibrium there are by definition no electron or hole currents. Also, the quasi-chemical potentials for electrons and holes are, in general, different and only approximately constant in parts of the device. If you assume a local quasi-equilibrium for either electrons or holes then currents are due to the gradient of the quasi-chemical poetential. In a current carrying device the quasi/chemical potentials cannot be exactly constant, they have to have at least a small gradient. | |
| Oct 6, 2016 at 22:51 | comment | added | Quantumwhisp | Isn't the introduction of quasi-chemical potenials and treating any electron current as diffusion process exactly the case of a thermodamic equilibrium with potential +quasi- chemical potential being constant throughout the device? | |
| Oct 6, 2016 at 15:37 | history | answered | freecharly | CC BY-SA 3.0 |