The correct answer is: D. Ions
A depletion layer is a region in a semiconductor where there are no free charge carriers. It is created at the junction of two semiconductor materials with different doping levels. The depletion layer is caused by the movement of ions across the junction.
When two semiconductor materials with different doping levels are brought into contact, electrons from the n-type material diffuse into the p-type material, and holes from the p-type material diffuse into the n-type material. This diffusion of charge carriers creates a region at the junction where there are no free charge carriers. This region is called the depletion layer.
The depletion layer has a barrier potential across it. The barrier potential is the energy required to move a charge carrier from one side of the depletion layer to the other. The barrier potential is determined by the difference in the doping levels of the two semiconductor materials.
The depletion layer plays an important role in the operation of semiconductor devices such as diodes and transistors.
A. Doping is the process of adding impurities to a semiconductor material in order to change its electrical properties. Doping can be used to create n-type or p-type semiconductors.
B. Recombination is the process of a free electron and a hole combining to form a neutral atom. Recombination can occur in both n-type and p-type semiconductors.
C. Barrier potential is the energy required to move a charge carrier from one side of the depletion layer to the other. The barrier potential is determined by the difference in the doping levels of the two semiconductor materials.
E. None of the above is not the correct answer.