[填空题]
Suppose that a silicon semi ka;) wv,bd6gn 5el;f y-ddze3conductor is doped with phosphorf di4uk(,6k q iz,al(uus so that one silicon atom iakf 6 ki4dl(uiz,, qu(n $ 10^6 $ is replaced by a phosphorus atom. Assuming that the "extra" electron in every phosphorus atom is donated to the conduction band, by what factor is the density of conduction electrons increased? The density of silicon is $ 2330\ \text{kg/m}^3 $, and the density of conduction electrons in pure silicon is about $ 10^{16}\ \text{m}^{-3} $ at room temperature. $\frac{N_{\text{doping}}}{N_{\ce{Si}}} = $ $ \times 10^6$
