Practice 2
2
P1 • Find a resistivity of intrinsic and p-type semiconductor with N A =10 16 cm -3 . (n i =1.510 10 cm -3 , n =1350 cm 2 /V.s, p =480 cm 2 /V.s For Si, n =1110 cm 2 /V.s, p =400 cm 2 /V.s) For intrinsic semiconductor For p-type semiconductor cm p n q p n i 5 10 10 19 10 28 2 350 10 5 1 480 10 5 1 10 6 1 1 1 1 . ) . . ( . ) ( cm p n q p n p 56 1 1110 10 25 2 400 10 10 6 1 1 1 1 4 16 19 . ) . ( . ) ( 3 16 10 cm N p A p 3 4 2 10 25 . 2 cm N n n A i p 5 5 10 46 1 56 1 10 28 2 . . . cm cm p i
description
Practice finding resistivity p-n
Transcript of Practice 2
P1 • Find a resistivity of intrinsic and p-type semiconductor with
NA=1016 cm-3.
(ni=1.51010 cm-3, n=1350 cm2/V.s, p=480 cm2/V.s
For Si, n=1110 cm2/V.s, p=400 cm2/V.s)For intrinsic semiconductor
cmpnq pn
i
5
10101910282
350105148010511061
111.
)..(.)(
For p-type semiconductor
cmpnq pn
p
561111010252400101061
11141619
.).(.)(
31610 cmNp Ap34
2
1025.2 cmN
nn
A
ip
55
10461561
10282
..
.cmcm
p
i
P2
scmcm
VsVcm
dV
Ev nnn /../ 64
2 10756102
11350
(a)
A uniform bar of n-type silicon of 2m length has a voltage of 1V applied
across it. If ND=1016 cm-3 and n=1350 cm2/V.s.
(a) Find the electron drift velocity(b) The time it takes an electron to cross the 2m length(c) The drift current density
scmm
vlength
tn /. 610756
2
(b)
cmm 4101
sscm
cmt 11
6
4
1096210756
102
./.
41619
102
11350101061
VEqnJ nn .
2410081 cmAEqnJ nn /. (c)
