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The figure below depicts the band diagram of a CIGS solar cell. Light enters from the left part of the figure. Which are the corresponding materials A, B and C?

A is CdS, B is CIGS and C is ZnO
B. A is CIGS, B is CdS and C is ZnO
C. A is ZnO, B is CIGS and C is CdS
D. A is ZnO, B is CdS and C is CIGS

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The figure below shows the absorption coefficient \(\alpha\) for amorphous and crystalline silicon. The figure also displays the solar irradiance of the AM1.5 spectrum due to photons with wavelengths lower than \(\lambda\).Which percentage of the solar spectrum does an a-Si:H layer of 300 nm thickness absorb? Remember that the AM1.5 spectrum has a total irradiance of \(1000W/m^2\). Hint: You can assume that the layer absorbs all photons with wavelength lower than that at which \(\alpha=1/d\).How thick should a c-Si layer (in \(\mu m\)) be in order to absorb that amount of the solar spectrum? ______

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The figure below shows the absorption coefficient \(\alpha\) for amorphous and crystalline silicon. The figure also displays the solar irradiance of the AM1.5 spectrum due to photons with wavelengths lower than \(\lambda\).Which percentage of the solar spectrum does an a-Si:H layer of 300 nm thickness absorb? Remember that the AM1.5 spectrum has a total irradiance of \(1000W/m^2\). Hint: You can assume that the layer absorbs all photons with wavelength lower than that at which \(\alpha=1/d\). ______

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Silicon wafers can be 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 \(1100^oC \) for 5 hours. The diffusion can be described by the Fick's law, the same law studied in block 2.3, but for non-charged atoms in this case. The law gives us the diffusion flux \(J\) for a certain material with diffusion coefficient \(D\) and density gradient \(dn/dx\):\(J=D\frac{dn}{dx}\)If the concentration of boron at the surface is \(10^{18} cm^{-3}\), calculate the depth below the surface (in \(\mu m\)) at which boron concentration is \(10^{17} cm^{-3}\). The boron diffusion flux is \(310^{9} cm^{-2}s^{-1}\) and the diffusion coefficient for boron diffusing in silicon at \(1100^oC \) is \(1.510^{-12} cm^2/s\). ______

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Why should the front n-layer of a c-Si solar cell be thinner than the p-layer?

A. The solar cell would actually have the same performance if the n-layer were thicker than the p-layer, as long as a p-n junction is created between these two.
Because the diffusion length of the photogenerated holes is larger in the n-layer than in the p-layer.
C. Because n-doping is required to absorb the incoming light.
D. 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.

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The figure below depicts the band diagram of a CIGS solar cell. Light enters from the left part of the figure. Which are the corresponding materials A, B and C?

A is CdS, B is CIGS and C is ZnO B. A is CIGS, B is CdS and C is ZnO C. A is ZnO, B is CIGS and C is CdS D. A is ZnO, B is CdS and C is CIGS

Why should the front n-layer of a c-Si solar cell be thinner than the p-layer?

A is CdS, B is CIGS and C is ZnO
B. A is CIGS, B is CdS and C is ZnO
C. A is ZnO, B is CIGS and C is CdS
D. A is ZnO, B is CdS and C is CIGS