Thermal Equilibrium Concentration in Germanium Semiconductor

Introduction
In a semiconductor material, the concentration of charge carriers (electrons and holes) determines its electrical properties. At thermal equilibrium, the concentration of electrons in the conduction band and the concentration of holes in the valence band are equal. This equilibrium concentration of charge carriers is denoted as p0 for holes and n0 for electrons.

Given Information
In the case of germanium semiconductor at room temperature (T = 300 K), we are given the acceptor concentration (Na) as 10^15 cm-3 and the donor concentration (Nd) as 0.

Equilibrium Concentration Calculation
To determine the thermal equilibrium concentration (p0) of holes, we use the equation:

p0 = Na - Nd

In this case, Nd is equal to 0, which means there are no donor impurities. Therefore, the equilibrium concentration of holes (p0) is simply equal to the acceptor concentration (Na).

Explanation
At thermal equilibrium, the number of holes created due to the ionization of acceptor impurities (Na) is balanced by the number of holes annihilated by recombination. Since there are no donor impurities (Nd = 0) to generate additional electrons and balance the number of holes, the concentration of holes (p0) will be equal to the acceptor concentration (Na).

This equilibrium concentration is important as it determines the electrical conductivity of the semiconductor. In this case, the germanium semiconductor will exhibit p-type conductivity due to the dominant presence of holes created by acceptor impurities.

Conclusion
In a germanium semiconductor at T = 300 K with an acceptor concentration (Na) of 10^15 cm-3 and no donor impurities (Nd = 0), the thermal equilibrium concentration (p0) of holes is equal to the acceptor concentration. This equilibrium concentration plays a vital role in determining the electrical properties of the semiconductor.