Concepts Of Physics MCQ Edition [Volume 2]PhysicsSemiconductors and Semiconductor Devices
When a p - n junction is reverse-biased, the current is nearly constant at 25 A . Upon being forward-biased at 200 mV , a current of 75 A is observed. Find the magnitude of the diffusion current when the diode is reverse-biased at 200 mV .
Options
- A50 A
- B100 A
- C0
- D25 A
Correct answer
C. 0
Step-by-step solution
The total current I in a p - n junction diode is given by the difference between the diffusion current and the drift current: I = I_ diffusion - I_ drift The drift current is due to minority carriers and remains nearly constant. From the given data, the reverse-biased current is constant at 25 A , which gives: I_ drift = 25 A When the diode is reverse-biased, the potential barrier widens, preventing the diffusion of majority carriers across the junction. Consequently, the total current is almost entirely due to the