@@ -66,7 +66,7 @@ Furthermore, the interactions between the electron and proton are screened by th
As a result, we need to introduce the following substitutions: $m_e \to m_e^*$, $\epsilon_0 \to \epsilon\epsilon_0$.
We thus estimate the energy of the bound state created by the impurity:
$$E = -\frac{m_e^*}{m_e \varepsilon^2} R_E = -0.01 \text{eV (in Ge)}$$
$r_B = 4$ nm (vs $r_B = 0.5$ Å in H).
$r_B = 4$ nm (vs $r_B = 0.5$ Å in H)$.
The electron is very weakly bound to the impurity! At room temperature (0.026 eV), the donor electron is easily thermally excited into the conduction band.
On the other hand, we can add a group III element to reduce the average number of electrons in the system.
