Question

I have a physics question. This is for extra credit which I really need to earn- If I made a solar cell how would I know which material is best to use if given choices like aluminum with a work function of 4.1eV at a cost of 2.40Kg or platinum with a work function of 6.4 eV at a cost of 58,430 or sodium with a workforce of 2.3eV at a cost of 0.20. If you could just explain how I figure it out not do all of the calculations-like do I multiply the work force by cost and the lower one is the best, etc.??

Answer 1

Solar cells are not generally made with photoelectric materials, although a photodiode is what you probably have in mind. They are usually used to measure strong light pulses.

Solar cells are made with semiconductors with band gaps for conducting electrons of about 2 eV. The lower the band gap, the longer the wavelength of electrons that can be raised to conduction band, where they can create a voltage to drive electric current. Think of how a material like silicon works. The photoelectrons are not driven off the surface, they are free to move within the material.

You need to do some reviewing of the solid state physics of how photoelectric devices work. I am not an expert in that field.

You seem to be confusing work force with work function, also.

Answer 2

Here is a good place to start reading about photoelectric devices.
http://www.explainthatstuff.com/how-photoelectric-cells-work.html

Most devices for converting light to useful power are of the photovoltaic type.

Answer 3

Thank you for directing me to that site-that one I didn't find while I was looking for info-I did confuse work force for work function- I appreciate you following up