1. -n- - σ =104 / n- σn =102 /. μn mp 0,39 0,19 2/(×). =300 ni =2,5×1019-3. ( ) =300 .
- σp=qρpm. p-
=σp/(qm)= 104 / (0,19×1,6×10-19)=3,29×1023-3.
n-
nn=σn/ (qmn)=100/(0,39×1,6×10-19)=1,6×1021-3.
n-
pn = i2 / =(2,5×1019)2/(1,60×1021)=3,91×1017-3.
2. 1, , , Ln = Lp = 1×10-3.
.
=3,91×1017-3;
np = ni2 / =1,9×1015-3.
Dp= (kT/q) mp Dn= (kT/q) m.
,
I0p/I0n=μppnLn/ (μnppLp)=0,19×3,91×1017/(0,39×1,9×1015)=100.
3. , I0 =25 , , 0,1 , T = 300 . : ) R0; ) r.
(U =0,1 )
I = I0 exp(qU / kT -1)=
=25∙10-6(exp(1,6∙10-19∙0,1/(1,38∙10-23∙300)-1)=1,17.
R0 = U / I =0,1/(1,17×10-3)=85.
:
r =1/(46×10-3)=21,6.
, , I>>I0,
.
4. pn- 0,2 , NA p- ND n- 3×1014-3. : ) pn- W U, 0,1 10 ; ) U 0,1 ; ) , , 0,1 10 , pn- S =1 2.
pn-
|
|
.
NA << ND,
.
. 3 es , pn- U =0,1
,
U = 10
.
pn- U =0,1
.
,
.
, p-n U =0,1
,
U = 10
.
5. n- , . "-" j0= 0,5 . qj 4,75 . . .
qj = qj qj =0,5 ,
qj = qj -qj0= 4,75-0,5=4,25 .
. 4, :
qj-q æ = (Ec-Efn),
Ec - Efn =4,25-4=0,2 ;
Efn - Ei= (Ec - Ei) - (Ec - Efn).
,
Efn - Ei= 0,562-0,2=0,362 .
,
,
:
n=ND=ni exp(0,362/0,0258)=1,5∙1010exp ( 0,362/0,0258 ) =
=1,8∙1016-3.
, 1.3.1, , (Em) U = 0. U = 0:
,
:
/.
6. - - NA = 1015 -3. 100 . qj = - 0,9. Qss = 8×10-8 /-2. Wmax, , (Qs), -, .
Wmax :
j=jT ln(NA/ni)=0,026ln(1015/1,5×1010)=0,29 B.
,
Cd = e0ed/d =8,85×10-14×4/10-5 = 3,45×10-8 /2.
:
QB=Qs =-qNAWmax =-1,6×10-19×1015×0,87×10-4 = 1,39×10-8 /2,
U=2jb-Qs/Cd = 2×0,29+1,39×10-8/3,45×10-8 = 0,98 B.
= =e0es/Wmax= 8,85×10-14×12/0,87×10-4 = 1,2×10-8 /2,
-
|
|
/2.
U/ =j+2j - (Qss +Qs)/ Cd =-0,9+0,576 -
-(5×1011×1,6×10-19 -1,39×10-8)/3,45×10-8 = -2,24B.