Recent content by HunterDX77M

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    Change in energy of a capacitor

    After asking him about it, my Professor responded: "The non integer charge can come from polarization of the metal piece by an electric field, that slightly moves the position of many charges." If that helps.
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    Change in energy of a capacitor

    This is indeed the problem as my Professor wrote it.
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    Change in energy of a capacitor

    Homework Statement A 2.1 aF capacitor has a net charge of 0.5e (a positive charge, the symbol e is taken as a positive number 1.6 x 10-19 coulomb). What is the energy needed to add one electron (charge -e) to this capacitor? Homework Equations Energy in a Capacitor: U = Q^2 \div 2C...
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    Calculate Minority Carrier Concentrations given the Fermi Level

    Homework Statement This question is based on a previous question in the same homework: The Problems deal with Silicon at 300K, using band gap energy Eg = 1.12 eV, electron density of states mass 0.327, hole mass 0.39, electron mobility 0.15 m2/Vs, hole mobility 0.05 m2/Vs and relative...
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    Fermi Energy level with respect to band gap energy

    You should have been given all the other variables to be able to solve this. Do you know the concentration and the density of states?
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    What is band bending and how does it relate to Fermi Energy?

    I found the following two equations in my lecture slides. Due to notational differences between my textbook and the lecture slides, I'm not sure if the variable EC represents the band gap energy (which is known in this problem). I am assuming that EFN is the Fermi level energy. E_{FN} = E_C...
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    What is band bending and how does it relate to Fermi Energy?

    Homework Statement Consider a pn junction in Si at 300K (other parameters given), with doping NA = 1021/m3 and ND = 1023/m3. Assume all impurities are ionized. On this basis find the Fermi level on each side. From this find the band bending VB and make a sketch of the pn junction. Homework...
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    Binding Energy of the hydrogenic acceptor state in Silicon?

    Oh, yeah. How could I forget about that? That's pretty basic. :-/ This is probably why it's a bad idea for me to do homework without sleeping for the majority of the day. Thanks for your help! :)
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    Binding Energy of the hydrogenic acceptor state in Silicon?

    Homework Statement Find the theoretical binding energy of the hydrogenic acceptor state in Si (eg, as produced by Aluminum impurities), using hole mass 0.39 and permittivity 11.8. Homework Equations E_b = \frac{k_c e^2}{2a_0} \\ a_0 = \frac{\hbar ^2}{mk_c e^2} The Attempt at a...
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    How can an extrinsic semiconductor still be electrically neutral?

    Homework Statement Explain why a pure semiconductor crystal will always have equal numbers of electrons and holes present as electrical carriers. Explain why a crystal with additional donor impurities will norally have more electrons in the conduction band than holes in the valence band, still...
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    Number of standing waves in a potential barrier

    Oops, forgot to take the square root didn't I? Thanks!
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    Number of standing waves in a potential barrier

    Homework Statement Consider a resonant tunneling diode structure (attached image). This shows 2 AIAs barriers of height 1.2 eV and width t = 2.4 nm, enclosing a well of width L = 4.4 nm. If the effective mass of the electron is taken as 0.9 times the free electron mass how many separate...
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    How do I calculate the Fermi Energy of a compound?

    Homework Statement 1) This question has to do with pure InAs, with a bandgap 0.33 eV, electron mass 0.02, hole mass 0.41. (a) Evaluate the number of electrons/m3 int he conduction band at 300K. For this purpose you can assume the Fermi Energy is exactly at the center of the energy gap...
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    Possible Rectangular Potential Barrier Transmission Problem

    Matching the units I found the following equation in the link: T = e^{-2k_2 L}; k_2 = \sqrt{\frac{2m(U-E)}{\hbar}} The Problem I am have, however, is that the units don't seem to cancel each other out. In the end T is simply a dimensionless quantity (probability), but that doesn't work...
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    Possible Rectangular Potential Barrier Transmission Problem

    Thank you for your link, rude man. I will look it over and see if it help me understand it. Also, I was going to post this in the Advanced Physics section, but the sticky post there said if a problem requires plugging into a formula, then it's probably introductory physics. Based on the...
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