A diode is an electronic component that allows current to flow easily in one direction but blocks current in the other direction. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Most diodes are made of a silicon semiconductor material. To make silicon a more effective semiconductor, the material goes through a process called doping. This results in the addition of impurities (holes) to the material. By adding holes, you create two different types of semiconductor material known as n-type and p-type. N-type materials have a net negative charge due to an excess of electrons and P-type materials have a positive charge due to a lack of electrons. When both types of material are joined, a pn junction is formed. Excess electrons in the n-type material flow across the junction to combine with the pa-type material due to the lack of electrons. The consequence of this is that very few charge carriers are present at the junction. The junction forms a depletion layer. The depletion layer acts as a barrier that prevents the flow of negatively charged electrons at the end of the cathode to the opposite side that has the positive potential. The diode does not conduct until a potential difference is applied between the anode and the cathode. This potential difference is necessary to overcome the electrostatic field formed across the depletion layer. The thinner the depletion layer, the greater the current passing through it. In order for a direct current to pass through the diode, the depletion region must be completely collapsed by the applied voltage to allow electrons to flow, this is called the forward voltage. To achieve this a certain minimum voltage is required. For most silicon diodes, the forward voltage is 0.6 volts. For germanium diodes, the forward voltage is only 0.3 volts. The chemical mixture of the PN junction in the diode is the reason for the forward voltage figure, which is why silicon and germanium diodes have a difference in the forward voltage figure. A diode will also conduct in reverse bias (potential difference) which is when the negative The battery terminal is connected to the P type and the positive is connected to the N type semiconductor. In which the diode blocks the current due to a thick layer of exhaustion. For standard diodes the reverse breakdown is much higher than the forward bias voltage. The point where the voltage increases but the current remains the same is called the reverse saturation current. This is because a point has been reached where additional applied voltage does not increase the electric current. In germanium diodes, due to the increase in temperature which creates more charge carriers than in silicon diode, the reverse saturation current is higher. In a forward biased diode the cathode (n-type semiconductor) connects to a negative potential and the anode (p semiconductor) connects to the positive potential. This doesn't block the current and has less resistance than a stock bias, but it drops the current. The forward bias voltage drop by the diode is due to the action of the depletion region. If no voltage is applied across the semiconductor diode, a thin depletion region exists around the PN junction region, which prevents current flow. If a reverse bias voltage is applied across the PN junction, this depletion region expands, further resisting any current through it. A very small amount of current can and does pass through a diode.