ianc said:
Just a quick question - Is the photoelectric effect (the thing that einstein explained using the work function, etc) the principle behind the photovoltaic cell (solar cell)?
Thanks!
the short answer: yes
the long answer: someone else who still remembers HSC Physics can answer you this one.
from memory, i can think of this:
1) the solar cell consists of an n-type and p-type semiconductor stuck together. on the middle where they join, there is a p-n junction, where some of the electrons in the n-type 'migrate' to the p-type to 'fill' the holes. hence we create a junction.
2) light shines on the junction. via the photoelectric effect, this causes some electrons to displace from the semiconductor. at the same time, it creates extra 'holes' as well, since the holes are not 'filled'.
3) this creation of 'holes' and 'electrons' create in essence a POTENTIAL DIFFERENCE - essentially, 'extra' electrons would travel through the EXTERNAL CIRCUIT to the p-junction side to meet up with the 'extra holes'
this creates the 'voltage', were it can be exploited by us hehehehe
now, i think ur wondering...why wouldnt the electron travel through the junction to meet up with its partner? answer is that the external circuit has the least electrical resistance.
2006ers, please clarify if what i have posted is in any shape or form, is correct.
hope this helps, M.D.
