Animation of forward biased diode. The diode is shown and wired as in Figure 3.5d except that the negative end of the battery goes to the left end, N region, of the diode and the positive end goes through a resistor to the right end, P region. The voltmeter starts out at zero and the electrons and holes start out as in figure 3.4b. As the voltage rises the ranks of holes and electrons move toward each other. At the left and right edges new electrons and holes, respectively, are injected by the external energy source. When the electrons and holes meet at the junction they combine and mutually annihilate. As soon as recombination begins the speed of movement of electrons and holes increases indicating that current is now flowing. The reading on the voltmeter stops increasing and current continues to flow indicated by electrons moving to the right and holes moving to the left.
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