Question # 1 / 9


Consider the diode shown in the Figure below.

Specify whether this could be:
a P-N junction
a N-P junction
a N-metal Schottky diode
a P-metal Schottky diode
diodeequi.t

Question # 2 / 9


Consider the pn junction shown below.

Specify the direction of the various currents and fluxes.

Electron drift flux: Electron drift current:
Electron diffusion flux: Electron diffusion current:
Hole drift flux: Hole drift current:
Hole diffusion flux: Hole diffusion current: diodedepl.t

Question # 3 / 9


Consider the figure below.

Indicate which diode is forward biased, in equilibrium or reverse biased.
Forward biased.
Reverse biased.
In equilibrium.
diodeflux.t

Question # 4 / 9


Consider the three band diagrams shown below.

Consider the electron and hole currents at the junction only. Link the correct statement with the appropriate band diagram.
The diffusion currents are smaller than the drift currents.
The diffusion currents are larger than the drift currents.
The diffusion currents are equal to the drift currents.
JnJp.t

Question # 5 / 9


Consider the Figure below.

Consider a forward biased diode. Identify the correct physical process described below. Assume that the electrons and holes do not recombine in the depletion region.
Variation of the electron and hole currents due the recombination with holes of excess electrons injected across the depletion region.
Variation of the electron and hole currents due the recombination with electrons of excess holes injected across the depletion region.
Total electron and hole current.
Hole current.
Electron current.
Identify the correct length.
Electron diffusion length.
Holes diffusion length.
Depletion width.
diodebias.t

Question # 6 / 9


Consider the 3 band diagrams shown below.

Identify the correct band diagrams.
The diode is in equilibrium.
The diode is forward biased.
The diode is reverse biased.
Specify the polarity of the applied voltage V.
V=0.
V>0.
V<0.
Identify the energies A1, B1, B2, C1, and C2.
Energy A1.
Energy A2.
Energy B1.
Energy C1.
Energy C2.
diodecap.t

Question # 7 / 9


The depletion width W in a pn junction diode varies as

where is the builtin voltage of the diode. The depletion charges on each side of the junction is then calculated to be

The diode current I is given by

where the excess carriers are given by




Identify the correct charges.
Qn charge of excess electrons injected in the p region under forward bias.
Qp charge of excess holes injected in the n region under forward bias.
Depletion charge due to the Acceptors.
Depletiong charge due to the Donors.
Identify the correct capacitances. The capacitance
is the capacitance.
is the capacitance.
The diode capacitance increases with increase applied voltages smaller than Vo. However when the intrinsic voltage of the diode becomes close to Vo the diode capacitance relative to the external voltage becomes .
schottky.t

Question # 8 / 9


Consider the four metal semiconductor band diagram shown below.
Match the correct description.
Metal to n-type semicondutor Schottky diode.
Metal to p-type semicondutor Schottky diode.
Metal to n-type ohmic contact.
Metal to n-type Schottky diode becoming ohmic due to tunneling.
zenerdiode.t

Question # 9 / 9


Consider the physical processes described in the Figure below
Specify which physical process is described.
Avalanche breakdown. Electrons and holes multiply.
Zener Breakdown. Electrons tunnel through the band gap. 

 
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