Volt-ampere Characteristics of Metal-semiconductor Rectifier Diodes. Part 2. Volt-ampere Characteristics of Metal-semiconductor Diodes

The volt-ampere characteristics of different diodes and zener diodes are obtained experimentally, and they differ significantly from experience to experience. It is unclear how to properly substantiate the reason for such differences. In this regard, a problem arose in developing the theoretical foundations for the production of this type of equipment on a sufficiently sound theoretical basis, taking into account the latest advances in electrical engineering and electronics. As a consequence, the process of formation of conduction currents and displacement currents in a metal–semiconductor contact is considered. Aluminum was used as a metal, and germanium and silicon were used as a semiconductor. With a direct applied external voltage, a theory for calculating the volt-ampere characteristics of germanium and silicon diodes has been developed. It is shown that the affinity energy of atoms of semi-conductor materials at the cathode increases slightly due to the coupling of negative ions with electric dipoles of atoms of the surface layer of aluminum molecules inside a columnar void, and an electric conduction current is formed by the movement of electrons from the cathode to the anode. The electron concentration due to the ionization of negative ions is determined not by the temperature of the diode itself, but by the reduced temperature of the electron gas inside the aluminum due to overcoming the contact potential difference at the p-n junction. A sequential accumulation of negative electron charge occurs at the anode, which determines the conversion of the conduction current into a displacement current, since the electron energy in this case does not exceed the energy of the aluminum work function of the crystal. At the reverse applied voltage, the affinity energy of the negative ions of the impurity atoms at the anode remains the same due to the ionization of the negative ions, taking into account an increase in the temperature of the electron gas at the p-n junction with an increase in the displacement current. An electric conduction current arises from an aluminum crystal acting as a cathode inside a columnar void due to thermoautoelectronic emission. The conduction current at the anode is converted into a displacement current, which enters the external electrical wires. The inner walls of the columnar void are a good dielectric and therefore they sufficiently conduct displacement current inside the columnar void. The conduction current in this case acts as an amplifier of the resulting electric current.