1 / 79

Memory Aid “a hairpin is lighter than a frying pan”

light m * (larger d 2 E/dK 2 ). heavy m * (smaller d 2 E/dK 2 ). Memory Aid “a hairpin is lighter than a frying pan”. 1. T=0 o K. T 1 >0. f (E). T 2 >T 1. 0.5. 0. E. E F. f (E) = 1/{1+exp[(E- E F )/ kT ]}. All energy levels are filled with e - ’s below the Fermi Energy at 0 o K.

hilary-crawford
Download Presentation

Memory Aid “a hairpin is lighter than a frying pan”

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. light m* (larger d2E/dK2) heavy m* (smaller d2E/dK2) Memory Aid“a hairpin is lighter than a frying pan”

  2. 1 T=0 oK T1>0 f(E) T2>T1 0.5 0 E EF f(E) = 1/{1+exp[(E-EF)/kT]} All energy levels are filled with e-’s below the Fermi Energy at 0 oK

  3. f(E) 1 T=0 oK T1>0 T2>T1 S(E) 0.5 0 E EV EF EC n(E)=S(E)f(E) E Putting the pieces together:for electrons, n(E)

  4. S(E) Putting the pieces together: for holes, p(E) fp(E) T=0 oK 1 T1>0 T2>T1 0.5 0 E EV EF EC p(E)=S(E)f(E) hole energy

  5. Finding no and po the effective density of states in the conduction band

  6. NA -> NA-ND = NA’ = ppo ND -> ND-NA = ND’ = nno

  7. w=(2εV/qNB)1/2

  8. Lasers

  9. n++ p n+ n+ W L (x) Ec(y) with VDS=0

  10. Increasing VGS decreases EB EB EF ~ EC y 0 L

  11. Band diagram of triode and saturation

  12. Threshold Voltage Definition VGS = VT when the carrier concentration in the channel is equal to the carrier concentration in the bulk silicon. Mathematically, this occurs when fs=2ff , where fsis called the surface potential

  13. Quantum Effects on Threshold Voltage

  14. (Maybe not so good for GaAs!) This is very confusing, because this effective mobility is being used to describe the velocity of carriers when the concept of mobility is not applicable!

More Related