Question

Consider a step pn junction made of GaAs at T = 300 K. At zero bias, only 20% of the total depletion region width is in the p-side. The built-in potential ϕi​=1.20V.
acceptor density in the p-side = 5.68x10^16
donor density in the n-side = 1.42x10^16
Determine the depletion region width, xn​, in the n-side in unit of μm.

Answer 1

Answer:

0.31 μm

Explanation:

this question wants us to Determine the depletion region width, xn​, in the n-side in unit of μm. using the information below.

density in the p-side = 5.68x10^16

density in the n-side = 1.42x10^16

$\sqrt{\frac{2*12.7*8.85E-10}{1.6E-14}(\frac{1}{5.68E16}+\frac{1}{1.42E16} )(1.2) }$

= √(1.42x10⁵)(1.76056335x10⁻¹⁷ + 7.042253521x10⁻¹⁷)(1.2)

= √150.74x10⁻¹¹

= 3.882x10⁻⁵

approximately 0.39μm

xn = 0.39 x 0.8

= 0.31μm

0.31 um is the depletion region width. thank you!