The density of an electron -hole pair in a pure germanium is ( 3 10¹⁶ ~m ⁻³ ) at room temperature . On doping with aluminium, the hole density increases to ( 4.5 10^ (22) m ⁻³ ). Now the electron density ( ( . ) in ( .m⁻³ ) ) in doped germanium is

Step-by-step solution

Given, density of electron-hole pair in pure germanium =3 10¹⁶ ~m ⁻³ On doping, hole density =4.5 10²² ~m ⁻³ Electron density =? We know n₁²=n_ h n_ e Where n_ i is electron-hole density in pure semiconductor; n_ h is hole density; n_ e is electron density n_ e = n_ i ² n_ h = (3 10¹⁶ ) 4.5 10²² =2 10¹⁰ ~m ⁻³ Therefore, electron density in doped germanium will be 2 10¹⁰ ~m ⁻³