半导体物理期末试题

Semiconductor Physics
[60 pts total, 6 pts each］
1, Give out three examples of zinc blende structure semiconductor materials.
2, Please write down the relation between effiective mass *m and ()
E k。

3，Please d escribe the role of phonons in the transiton of indirect bandgap materials。

4，What is a donor l evel （describe with characters and figure)？What el ements can be as donor impurities for Si.
5, Please write down the Fermi distribution function and indicate the applicable case。

K , Please describe the physical meaning of Fermi distribution function.
6, At 0
7, Please tell us there are how many kinds of recombinations. What are they？And please figure them out.
8, Please figure out the I—V curve of the tunneling diode and analyze it in d etail.
9, Please draw a sketch of a metal and a semiconductor before contact. Work function，electron affinity, etc。

Shoul d be indicated in the figure。

10，Please draw the bandgap of an Ohmic contact which formed by metal-n type semiconductor。

［40 pts total ， 10 pts each ］
1， Assuming a is the lattice constant of one dimentional crystal. The bootom of the conduction band and top of the vallance band are
222100()()3c ћk k ћk E k m m -=+,2222
100
3()6v ћk ћk E k m m =- respectively. Where 0m is the mass of electrons, 112
k a =，0.314a nm =.Please calculate （1） the band gap
（2） effective mass of electrons at the bottom of the conduction band
(3） effective mass of electrons at the top of the valance band
(4) the quasi —momentum when electrons transit from the top of balance band bottom of conduction band 。

2， The bandgap of GaP 2.26g E eV =， dielectric constant is 11.1r ε=， the effective
mass of holes *00.86p m m =。

Pl ease cal culate
（1) the ionizing energy of acceptor impurities
（2) orbit radius of the hole ground state bounded by acceptor impurities
3, For an n-type Si ,16310D N cm -=.14310n p cm -∆=∆= because of illumination. Please calculate the conductivities of dark and illumination.
4， Let 153510D N cm -=⨯，17310A N cm -=。

Please calculate D V of the abrupt Ge p —n
junction at room temperature.。