Assuming that the electron and hole masses equal the free electron mass, what is the intrinsic carrier density of diamond with a bandgap of 5.4 eV? Assume temperature 300 K.

Respuesta :

Answer:

The intrinsic carrier density of diamond is [tex]1.330\times10^{-26}[/tex].

Explanation:

Given that,

Energy band gape = 5.4 eV

Temperature = 300 K

We need to calculate the intrinsic carrier density of diamond

Using formula of density

[tex]n_{1}^2=N_{c}N_{v}e^{-\dfrac{E_{g}}{kT}}[/tex]....(I)

We need to calculate [tex]N_{c}[/tex]

[tex]N_{c}=2(\dfrac{2\pi m_{n}kT}{h^2})^{\frac{3}{2}}[/tex]

Put the value into the formula

[tex]N_{c}=2(\dfrac{2\pi\times9.1\times10^{-28}\times300\times1.3807\times10^{-16}}{(6.63\times10^{-27})})^{\frac{3}{2}}[/tex]

[tex]N_{c}=2.501\times10^{19}\ cm^{-3}[/tex]

We need to calculate [tex]N_{v}[/tex]

[tex]N_{v}=2(\dfrac{2\pi m_{n}kT}{h^2})^{\frac{3}{2}}[/tex]

[tex]N_{v}=2(\dfrac{2\pi\times9.1\times10^{-28}\times300\times1.3807\times10^{-16}}{(6.63\times10^{-27})})^{\frac{3}{2}}[/tex]

[tex]N_{v}=2.501\times10^{19}\ cm^{-3}[/tex]

So. [tex]N_{c}=N_{v}[/tex]

Now, Put the value of  [tex]N_{c}[/tex] and  [tex]N_{v}[/tex] in equation (I)

[tex]n_{i}^2=(2.501\times10^{19})^2 e^{\dfrac{-5.4}{0.0259}}[/tex]

[tex]n_{i}^2=1.7715080315\times10^{-52}[/tex]

[tex]n_{i}=1.330\times10^{-26}[/tex]

Hence, The intrinsic carrier density of diamond is [tex]1.330\times10^{-26}[/tex].