Question

To a sample of intrinsic silicon we add 101 7 atoms per cc of phosphorus and 9 Χ 101 6 atoms per cc of boron.

Calculate the density of the majority and of the minority carriers at:
a) 1 = 300K, b) T= 600K

Answer 1

The density of majority and minority carriers in intrinsic silicon can be calculated using the formula Density = concentration * charge. At 300K, the majority carrier density is 1.6 × 1011 cm-3 and the minority carrier density is -9 × 1010 cm-3. At 600K, the majority carrier density is 1.2 × 1012 cm-3 and the minority carrier density is -6.6 × 1011 cm-3.

Step-by-step explanation:

The density of majority carriers and minority carriers can be calculated using the formula:

Density = concentration * charge

Intrinsic silicon has equal number of majority carriers (electrons) and minority carriers (holes). Assuming the concentration of majority carriers (phosphorus) is 1017 atoms/cc and the concentration of minority carriers (boron) is 9 × 1016 atoms/cc, the density of majority carriers would be positive and the density of minority carriers would be negative.

For temperature (T) = 300K, the majority carrier density is 1.6 × 1011 cm-3 and the minority carrier density is -9 × 1010 cm-3. For temperature (T) = 600K, the majority carrier density is 1.2 × 1012 cm-3 and the minority carrier density is -6.6 × 1011 cm-3.