Electron Flow – Understanding Electron Flow in Diodes


Using conventional notation in the diagram below, I understand that the circuit is not complete because the diode is in reverse bias. But knowing that the electrons actually flow from the negative to the positive terminal(direction of the arrows), wouldn't the electrons take a path from the negative terminal of the battery, go through the lamp and stop at the diode(the red path in the picture). If they would, then why doesn't the lamp light up with the first electrons that are able to flow through it before the voltage in the wire is built up and the current stops.

Basic Circuit with arrows pointing in direction of electrons moving through the circuit. Red outlining the path of electrons.

Best Answer

Electrons can't flow in that direction (right to left) though a diode.

Yes, a small transient current flows while the voltage builds up across the diode (it acts like a small capacitor). In practice this charge is very small (pico coulombs), and would not actually illuminate a lamp, neither could you see the extremely brief pulse even if it could.