Solar Cells (1 Viewer)

[Trebla]

I have some contradicting information about solar cells. According to Jacaranda, the n layer faces the sun and UV light causes this layer to release electrons which move onto a metallic grid to the external circuit and back into the p layer.
However, according to Success One and the HSC exam, the p layer faces the sun. The junction has an electric field caused by opposing charges. The electrons from the n layer transfer to the p layer by attraction and the holes transfer to the n layer by attraction. When UV light hits the p layer, electrons move to the n layer and then the external circuit, and eventually returning to the p layer.
Presumably, Success One would be correct because the diagram was in the 2004 HSC exam. So is Jacaranda wrong (for a useful textbook uh-oh..)? Or are they both right?

 

[alcalder]

I would say they are both right. In both cases an electron is freed. With the N-type layer on top, the electron is freed to go down into the P-type layer and into the circuit.

With the P-type layer on top, the electron is freed to flow into the circuit (and the hole moves into the N-type layer, ie an electron from the N-type layer fills the hole in the P-type layer).

http://science.howstuffworks.com/solar-cell1.htm

This link may help.

 

[Trebla]

If they're both right, then that means you have to know both ways. In the 2004 HSC, there was a question on solar cells with a diagram provided showing the p layer facing the sun. Those who solely relied on Jacaranda would probably have no clue how to answer this question then and if they write Jacaranda's explanation then they'll get it wrong.
Also, that website supports the theory that the p type is facing the sun.