NTA Abhyas JEE Main2020PhysicsSemiconductorsPractice
A p - n junction has acceptor impurity concentration of 10 17 c m - 3 in the p side and donor impurity concentration of 10 16 c m - 3 in the n side. The contact potential at the junction is ( k T = thermal energy, intrinsic carrier concentration n i = 1.4 × 10 10 c m - 3 )
Options
- Ak T e ln ( 4 × 10 12 )
- Bk T e ln ( 2.5 × 10 23 )
- Ck T e ln ( 10 23 )
- Dk T e ln ( 10 9 )
Correct answer
A. k T e ln ( 4 × 10 12 )
Step-by-step solution
Constant potential at the junction V c o n s t a n t = k T e ln n a n d n i 2 V c o n s t a n t = k T e ln 10 17 × 10 16 1.4 × 10 10 2 = k T e ln ( 4 × 10 12 )