Seminar 3 Flashcards
How are devices with a superstrate configuration processed?
By forming a TCO/junction-partner/thin-film/back contact stack on a transparent sheet (i.e superstrate) through which light enters the device.
In solar cells what does TCO stand for?
Transparent-conductive-oxide
How are devices with a substrate configuration processed?
The deposition sequence is reversed and the stack is formed on a substrate, which does not have to be transparent.
In what ways is the superstrate design better than the substrate design
- It can significantly improve light management.
- The highest efficiency devices and commercialised modules have typically been fabricated using the superstrate configuration.
What are the external parameters for solar cells?
- Short circuit current.
- Open circuit voltage.
- Fill factor.
- Efficiency.
- Series and parallel resistance.
How are external parameters of the solar cells determined?
Via measurement of the solar cells I-V curve.
What is open circuit voltage?
The voltage that occurs when there is no current.
In an ideal solar cell, what is the open circuit voltage independent of?
Illumination intensity.
How do you read open circuit voltage from a solar cells I-V curve?
Read the voltage axis at the point where the current is zero.
What is short circuit current density?
The short circuit current divided by the area of the solar cell.
What is short circuit current?
The current when the impedance is low and voltage is 0.
How do you find short circuit current from a solar cells I-V curve?
Look at the current at the point where the voltage is equal to zero.
What is the current at the maximum power point of the cell?
The maximum current, Imax.
Whereabouts is the maximum power point on a solar cells I-V curve?
The point where the load line crosses the I-V curve.
What is fill factor?
The measure of the quality of a solar cell. The ratio of maximum power to the theoretical power.
