Lesson: Doped Semiconductors

A doped semiconductor that contains donor ions and is at thermal equilibrium is modeled using three variables. The density of free electrons in the semiconductor is represented by . The density of donor ions in the semiconductor is represented by . The density of vacancies in the semiconductor is represented by . Which of the following formulas correctly represents the relationship between these variables in the semiconductor?

A doped semiconductor that contains acceptor ions and is at thermal equilibrium is modeled using three variables. The density of free electrons in the semiconductor is represented by . The density of acceptor ions in the semiconductor is represented by . The density of vacancies in the semiconductor is represented by . Which of the following formulas correctly represents the relationship between these variables in the semiconductor?

The diagram shows a lattice of silicon atoms that contains one atom of phosphorus. One of the electrons from the outermost shell of the phosphorus atom moves freely in the lattice. What is the net relative electronic charge of the phosphorus?