(d)
12.7
12.8
(a)
(b)
(c)
(d)
12.9
(a)
(b)
(c)
(d)
12.10
12.11
(a)
(b)
(c)
(d)
12.12
(a)
(b)
(c)
(d)
12.13
(a)
(b)
(c)
Because most of the photons are absorbed close to the front surface of the solar cell and the thickness
should be smaller than the hole diffusion length in the emitter.
Silicon wafers can be made p-doped by diffusing boron into the wafer. Imagine that boron is diffused into a
wafer with no previous boron in it at a temperature of 1,100°C for five hours. The diffusion can be described by
Fick’s law (Eq. (12.6). If the concentration of boron at the surface is 10 18 cm −3 , calculate the depth below the
surface at which the boron concentration is 10 17 cm −3 . The boron diffusion flux is J = 3 × 10 9 cm −2 s −1 and the
diffusion coefficient for boron diffusing in silicon at 1,100°C is D = 1.5 × 10 −12 cm 2 s −1 .
What kinds of losses are related to the design of the top contact of a solar cell?
Shading losses.
Resistive losses in the top contact.
Resistive losses in the emitter.
All of the above.
Which of the following statements is false?
Increasing the length of the finger increases the resistive losses.
Increasing the finger spacing decreases the power losses due to shadowing.
Increasing the finger width increases the power losses due to shadowing.
Increasing the finger width increases the resistive losses.
Consider a c-Si solar cell with fingers having a resistance of R = 0.1 Ω. What would be the finger resistance if
the finger width was doubled and the finger height was set to one-third of its initial value?
We have discussed that a bare crystalline silicon surface contains many defects which act as SRH
recombination centres. How can the surface recombination at the air/n-silicon interface be reduced? (More than
one correct answer possible.)
By decreasing the doping of the n-layer.
By increasing the doping of the n-layer.
By depositing a thin insulating layer on top of the n-layer.
By depositing a thin conductive layer on top of the n-layer.
In state-of-the-art crystalline silicon solar cell technology, which is based on p-type silicon, a back surface field
(BSF) is implemented. This BSF is implemented, because in this way …
… the barrier for hole collection at the back contact is reduced, increasing the surface recombination
velocity at the back contact.
… the barrier for electron collection at the back contact is reduced, decreasing the surface
recombination velocity at the back contact.
… a barrier is created for hole collection at the back contact, increasing the surface recombination
velocity at the back contact.
… a barrier is created for electron collection at the back contact, decreasing the surface recombination
velocity at the back contact.
Which of the following concepts are used in the PERL (passivated emitter rear locally diffused) solar cell?
(More than one correct answer possible.)
Inverted pyramids.
Multi-junctions.
Bifacial configuration.
12.7
12.8
(a)
(b)
(c)
(d)
12.9
(a)
(b)
(c)
(d)
12.10
12.11
(a)
(b)
(c)
(d)
12.12
(a)
(b)
(c)
(d)
12.13
(a)
(b)
(c)
Because most of the photons are absorbed close to the front surface of the solar cell and the thickness
should be smaller than the hole diffusion length in the emitter.
Silicon wafers can be made p-doped by diffusing boron into the wafer. Imagine that boron is diffused into a
wafer with no previous boron in it at a temperature of 1,100°C for five hours. The diffusion can be described by
Fick’s law (Eq. (12.6). If the concentration of boron at the surface is 10 18 cm −3 , calculate the depth below the
surface at which the boron concentration is 10 17 cm −3 . The boron diffusion flux is J = 3 × 10 9 cm −2 s −1 and the
diffusion coefficient for boron diffusing in silicon at 1,100°C is D = 1.5 × 10 −12 cm 2 s −1 .
What kinds of losses are related to the design of the top contact of a solar cell?
Shading losses.
Resistive losses in the top contact.
Resistive losses in the emitter.
All of the above.
Which of the following statements is false?
Increasing the length of the finger increases the resistive losses.
Increasing the finger spacing decreases the power losses due to shadowing.
Increasing the finger width increases the power losses due to shadowing.
Increasing the finger width increases the resistive losses.
Consider a c-Si solar cell with fingers having a resistance of R = 0.1 Ω. What would be the finger resistance if
the finger width was doubled and the finger height was set to one-third of its initial value?
We have discussed that a bare crystalline silicon surface contains many defects which act as SRH
recombination centres. How can the surface recombination at the air/n-silicon interface be reduced? (More than
one correct answer possible.)
By decreasing the doping of the n-layer.
By increasing the doping of the n-layer.
By depositing a thin insulating layer on top of the n-layer.
By depositing a thin conductive layer on top of the n-layer.
In state-of-the-art crystalline silicon solar cell technology, which is based on p-type silicon, a back surface field
(BSF) is implemented. This BSF is implemented, because in this way …
… the barrier for hole collection at the back contact is reduced, increasing the surface recombination
velocity at the back contact.
… the barrier for electron collection at the back contact is reduced, decreasing the surface
recombination velocity at the back contact.
… a barrier is created for hole collection at the back contact, increasing the surface recombination
velocity at the back contact.
… a barrier is created for electron collection at the back contact, decreasing the surface recombination
velocity at the back contact.
Which of the following concepts are used in the PERL (passivated emitter rear locally diffused) solar cell?
(More than one correct answer possible.)
Inverted pyramids.
Multi-junctions.
Bifacial configuration.