The breakdown voltage of the P-N junction diode decreases due to the increase in the reverse leakage current.


A P-N junction diode is a two-terminal electronic device that allows current to flow in one direction while blocking it in the opposite direction. When the reverse bias voltage applied across the diode exceeds a certain threshold, known as the breakdown voltage, the diode enters into the breakdown region. In this region, the diode conducts a large amount of current, which can potentially damage the device.


Reverse leakage current is the small current that flows through the diode when it is reverse biased. It is caused by the minor imperfections in the junction and the thermal generation of electron-hole pairs. As the reverse leakage current increases, the breakdown voltage of the diode decreases.


The breakdown voltage of a diode is determined by the maximum reverse bias voltage that it can withstand before entering the breakdown region. When the reverse leakage current increases, it causes a higher level of current flow in the breakdown region. This increased current flow leads to a decrease in the breakdown voltage.


The increase in reverse leakage current is primarily due to the worsening of the junction's characteristics. As the diode ages or experiences higher temperatures, the number of impurity atoms in the junction increases, resulting in a higher leakage current. This increase in reverse leakage current reduces the effective thickness of the depletion region, which is responsible for blocking the current flow in the reverse biased condition. As a result, the breakdown voltage decreases.


In summary, the breakdown voltage of a P-N junction diode decreases due to the increase in reverse leakage current. The reverse leakage current is caused by imperfections in the junction and thermal generation of electron-hole pairs. As the reverse leakage current increases, it leads to a higher current flow in the breakdown region, resulting in a decrease in the breakdown voltage.