The typical ionisation energy of a donor in s | vedclass

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(C) When a donor impurity ($+5$ valence) is added to pure silicon ($+4$ valence),the donor atom replaces a silicon atom in the crystal lattice. Since

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$0.1$

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(C) When a donor impurity ($+5$ valence) is added to pure silicon ($+4$ valence),the donor atom replaces a silicon atom in the crystal lattice. Since the donor atom has one extra valence electron,it creates a net positive charge of $+1e$ at the site. The four valence electrons form covalent bonds with neighboring silicon atoms. The fifth electron is loosely bound to the donor site and can be modeled as an electron revolving around a $+1e$ charge in a medium with permittivity $\varepsilon = \varepsilon_0 \varepsilon_r$. The energy levels are given by $E_n = -\frac{13.6 	imes m^* / m_e}{\varepsilon_r^2 n^2} 	ext{ eV}$. For silicon,the relative permittivity $\varepsilon_r \approx 12$. Substituting $n=1$ and accounting for the effective mass of the electron in the crystal,the ionization energy is approximately $E \approx -\frac{13.6}{12^2} \approx -0.094 	ext{ eV}$,which is approximately $0.1 	ext{ eV}$.

The typical ionisation energy of a donor in silicon is.....$eV$

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