In a semiconductor diode, the doping concentrations on -side and -side are atoms/ and atoms/, respectively.

Question

In a semiconductor $p - n$ diode, the doping concentrations on $p$ -side and $n$ -side are $10^{15}$ atoms/ ${cm}^{3}$ and $10^{18}$ atoms/ ${cm}^{3}$ , respectively. Which one of the following statements is true? [2026]

Smart Achievers · Accepted Answer

(2)

$The depletion layer must maintain charge neutrality$

$p$

$\frac{x_{p}}{x_{n}} = \frac{N_{n}}{N_{p}} = \frac{10^{18}}{10^{15}} = 10^{3} > 1$

$x_{p} > x_{n}$

$∴$ $x_{p} > x_{n} in depletion region$

Solution

Q.
In a semiconductor $p - n$ diode, the doping concentrations on $p$ -side and $n$ -side are $10^{15}$ atoms/ ${cm}^{3}$ and $10^{18}$ atoms/ ${cm}^{3}$ , respectively. Which one of the following statements is true [2026]

1 Widths of depletion region on either side of the interface are equal

2 The depletion region width is more on $p$ -side compared to that in $n$ -side

3 The depletion region width is more on $n$ -side compared to that in $p$ -side

4 No depletion region forms because of unequal doping concentrations on $p$ and $n$ -sides

Ans.
(2)

$The depletion layer must maintain charge neutrality$

$N_{p} x_{p} = N_{n} x_{n}$

$\frac{x_{p}}{x_{n}} = \frac{N_{n}}{N_{p}} = \frac{10^{18}}{10^{15}} = 10^{3} > 1$

$x_{p} > x_{n}$

$∴$ $x_{p} > x_{n} in depletion region$

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Solution

Q. In a semiconductor p-n diode, the doping concentrations on p-side and n-side are 1015 atoms/cm3 and 1018 atoms/cm3, respectively. Which one of the following statements is true [2026]

1 Widths of depletion region on either side of the interface are equal

2 The depletion region width is more on p-side compared to that in n-side

3 The depletion region width is more on n-side compared to that in p-side

4 No depletion region forms because of unequal doping concentrations on p and n-sides