Question

Imagine a solar cell where the p-n junction diode is kept in the sun. Upon absorbing su light, electron hole pairs are generated inside the depletion region around the junction.

You have a Silicon p-n junction diode where the Fermi energy on the p-doped side is 0.02 ev above the upper edge of the valence band and the Fermi energy is 0.01 eV below the lower edge of the conduction band in the n-doped side. The band gap in Silicon is 1.14eV.

Now we disconnect the wire from the p-n junction diode and keep it kN that open-circuit condition. We connect a voltmeter on between the p-type and n-type terminals to measure the photo- voltage generated by this solar cell.

In open-circuit condition, no current flows, even under light irridation. What should be the electric filed in the junction region such that the current flow is 0?

Draw the band diagram in this case.

Answer 1