Pure silicon at 300 K has equal electron and equal hole concentration of 1.5 x \( {10 }^{16  } \) \( { m}^{ -3} \) doping by indium increases the hole concentration to 4.5 x \( { 10}^{22 } \) \( { m}^{ -3} \). Then the electron concentration in doped silicon is (in \( { 10}^{ -3} \))

5  x \( { 10}^{ 9} \)

n_e x n_h = n_i²

n_i = 1.5 x \( {10 }^{16  } \) \( { m}^{ -3} \)

n_h = 4.5 x \( { 10}^{22 } \) \( { m}^{ -3} \)