Answered: The energy dispersion for electrons in… | bartleby

Related questions

Question

The energy dispersion for electrons in one dimensional lattice with lattice parameter a is
given by E(k)= E,
1
W cos ka, where W and E, are constants. The effective mass of
the electron near the bottom of the band is

Expert Solution

Trending now

This is a popular solution!

Step by step

Solved in 2 steps with 2 images

SEE SOLUTION Check out a sample Q&A here

Blurred answer

Similar questions

The 2DEG in (iii) is patterned to produce a clean, quasi-1D channel. The current I through the channel is = Nev, where N = the number of electrons, e the electronic charge and = the electrons' group velocity. The number of electrons N(ɛ) = f(ɛ, µ)g(ɛ), where f (ɛ, u) =Fermi-Dirac distribution = 1 and g(ɛ) density of states = dn/dɛ. 1+exp() kBT (a). Write down the dispersion relation for free electrons of mass m. What is their group velocity v? (b). Find an expression for g(ɛ) involving the group velocity. Leave your answer in terms of v.
Graph below shows the electron occupancy probability P(E) as a function of energy for Bismuth (mBi = 3.47 × 10-25 kg) at the temperature T = 0 K. What is the number of conduction electrons per unit volume for Bismuth? 1 1 2 3 4 5 6 7 8 E (ev) P(E)
Consider a 100 Ǻ GaAs/AlGaAs quantum well where the electron effective mass is 0.067 m0. There are 2 x 1012 electron/cm2 in the well. At low temperatures, calculate the magnetic field at which the Fermi level just enters the third Landau level of the ground state sub-band.
A power diode used in a cell phone tower power supply dissipating power during the conductionprocess requires its junction temperature on not to exceed 180 degrees C. The power diode data sheet givesconduction-state voltage drop of 1.8V and for the DO-4 diode case, the junction-to-case thermal resistance, R-theta , jcis 0.8 degrees C/W. The diode is mounted over a heat sink having thermal resistances, case-to-sink R-theta,cs = 0.3degrees C/W and sink-to-ambient R-theta, sa= 0.6degrees C/W. Calculate the maximum current that diode can withstand safely without overheating if theambient temperature is 30 degrees C. Calculate the difference of temperature from case to sink. If the design requires to limit the junction temperature to 150 degrees C, select a value of R-theta,sa for aheat sink which should be used.
A 10 monolayers thick layer of Ag is deposited on Mo. The intensity of electrons emitted by the Ag and Mo can be measured separately. The ratio IAg/IMoi =100 for the deposited film. The mean free path of the electrons is 0.6 nm and the thickness of one layer is 0.18 nm. After heating the sample, the Ag layer has agglomerated in islands that cover a fraction q of the surface. Between the islands the Mo is “visible”. The intensity ratio after agglomeration is IAg/IMof = 1. Calculate the sensitivity of the electron spectroscopy technique for Ag with respect to Mo. I.e. how many electrons are emitted from one layer of Ag atoms compared to one layer of Mo atoms. And use this to determine what fraction of the surface is covered by islands?
Between germanium and zinc sulfide, which material would be useful for use as an optical detection device (eg. photodiode) in the near infrared at room temp? Note: Both Ge and ZnS are considered semiconductor materials, but their energy band gaps are quite different. More Info: Eg for Ge ( T = 300K) = 0.66 eV, and Eg for ZnS ( T = 300K) = 3.6 eV.