Download Exercises on chapter 1:| Calculate the intrinsic carrier concentration

Exercises on chapter 1:|
1.1 Calculate the intrinsic carrier concentration in silicon and germanium at
a) T=100K , b) T= 500K
1.2 Find the concentrations electrons and holes in a simple of silicon that has a concentration of
donor atoms equal to 5X1015cm-3. Is the semiconductor n-type or p-type.
1.3
a)
b)
c)
The electron concentration in silicon at T= 300K is no=5X1015cm-3.
Determine the hole concentration
Is the material n-type or p-type?
What is the impurity doping concentration?
1.4 Determine the built-in potential barrier Vbi in a silicon pn junction for
a) Nd=Na=1016cm-3
b) Nd= 1018cm-3 , Na=1016cm-3
1.5 Consider a uniformly doped GaAs pn junction with doping concentrations of
Na=5X1018cm-3 and Nd= 5X10-3. Plot the built-in potential barrier Vbi versus Temperature
for 200K ≤ T ≤ 500K.
1.6 For a pn junction diode, what must be the forward-bias voltage to produce a current of
150µA if
a) Is = 10-11A
b) Is = 10-13A.
1.7 A silicon pn junction diode has an emission coefficient of n=1. The diode current is ID= 1mA when
VD= 0.7V. What is the reversed-bias saturation current.
1.8
Determine the diode current at room temperature for silicon diode with Is= 50nA and an
applied forward bias of 0.6 V. Repeat the above calculation for T=1000C. Assume that Is
has increased to 5µA
1.9 In the diode circuit Shown below , find the diode voltage and the supply voltage V such that the
current is ID = 0.4mA. Assume the diode cut in voltage Vγ= 0.7V .
a) Determine the power dissipated in the diode.
Repeat part a) if Vps=0.5V