Determine velocity of electron if drift time is 2×10 -10 s and intrinsic region width of 25×10 -6 μm.

Optoelectronics and Optical Communication 

Determine velocity of electron if drift time is 2×10 -10 s and intrinsic region width of 25×10 -6 μm.

a) 12.5×10 4 
b) 11.5×10 4 
c) 14.5×10 4 
d) 13.5×10 4

Answer : - 12.5×10 4

The drift time is given by 
t drift = w/v d 
v d = 25×10 -6 /2×10 -10 = 12.5×10 4 ms -1