MC test: Photovoltaic cells & DSSCs

Multiple choice test on C.8 Photovoltaic cells & DSSCs

Use the following 'quiz' to test your knowledge and understanding of this sub-topic. As this relates to a sub-topic on the options you may need access to the IB data booklet.

If you get an answer wrong, read through the explanation carefully to learn from your mistakes.

Which is the order of increasing first ionization energies (lowest first)?

Group 1 metals have the lowest values and the value decreases within the group as the atomic number increases. Sulfur is a non-metal and has the highest value.

 

Which element can be used to dope silicon to form a p-type semiconductor?

Doping with a group 13 element produces a positive 'hole' in the valence shell electrons making it a p-type semiconductor.

 

Which statements are correct about the electrical conductivity of silicon?

I. The electrical conductivity increases with increasing temperature.

II. Adding a small amount of arsenic to the silicon will increase its electrical conductivity.

III. Adding a small amount of aluminium to the silicon will increase its electrical conductivity.

Doping with As and Al forms n-type and p-type semiconductors respectively both of which increase the electrical conductivity. When metals are heated their electrical conductivity decreases but when semiconductors are heated their electrical conductivity increases.

 

Which is used to make the anode in a Grӓtzel DSSC?

Titanium(IV) oxide is used as the conductor but the anode itself is made from SnO2 doped with F− ions.

 

Which reaction occurs to convert the dye in a Grӓtzel DSSC back to its normal state after it has absorbed an electron?

When the dye absorbs light then loses an electron it has been oxidized. Two iodide ions in the electrolyte are oxidised to iodine which combines with a third iodide ion to form the triiodide ion. The electrons released in this reaction reduce the dye back to its unoxidized state.

 

Which will absorb visible light?

I.

II.

III.

I (which is vitamin C) does not have extensive conjugation. II is an anthocyanin (pelargonidin), an orange plant pigment, which has been used in DSSCs and III is a commonly used dye in DSSCs - both II and III show extensive conjugation.

 

Which is one of the essential differences between a silicon photovoltaic cell and a dye-sensitized solar cell (DSSC)?

In a photovoltaic cell the light is absorbed and the charges separated in the silicon semiconductor. The other three statements are true for both types of cell.

 

Why are nanoparticles of titanium(IV) oxide used in a Grӓtzel DSSC?

The nanoparticles ensure that the dye is spread over a large surface area so that it can absorb the light to maximum effect.

 

Which describe the advantages that DSSCs have over silicon-based photoelectric cells?

I. They are cheaper and easier to produce.

II. They are more rigid.

III. They absorb visible light over a larger range of wavelengths.

DSSCs are semi-flexible so they are less rigid than silicon-based photoelectric cells.

 

Which material is used to make the cathode in a Grӓztler DSSC?

The cathode is made of a thin film of platinum which is coated on glass.

 

Total Score:
All materials on this website are for the exclusive use of teachers and students at subscribing schools for the period of their subscription. Any unauthorised copying or posting of materials on other websites is an infringement of our copyright and could result in your account being blocked and legal action being taken against you.