A semiconductor has equal electron and hole concentration of `6xx10^(8) m^(-3)` on doping with certain impurity electron concentration increases to `9xx10^(-12)` m calculate the new hole concentration

Explanation

To solve the problem, we need to calculate the new hole concentration (np) after doping a semiconductor that initially has equal electron and hole concentrations.

### Step-by-Step Solution:

1. **Identify Initial Conditions:**
- The initial electron concentration (ne) and hole concentration (np) are both given as:
\[
n_i = n_p = 6 \times 10^8 \, \text{m}^{-3}
...