Answer to Question #162976 in Physics for Ajay

Question

A germanium crystal with doping of 10¹⁸arsenic atoms per cm³

is required. For

initial Ge load of 20 kg, calculate the mass of arsenic to be added. Assume that the

value of k₀ remains constant throughout the growth process. Consider the density of

molten germanium to be 5.7 g cm^-3

and atomic weight of arsenic 74.934u.

Answer 1

$$V=\frac{m_{Ge}}{\rho_{Ge}}=\frac{20000}{5.7}=3509\ cm^3$$

$$m_{As}=\frac{N}{N_A}M_{As}=\frac{nV}{N_A}M_{As}\\ m_{As}=\frac{10^{18}\cdot3509}{6.02\cdot10^{23}}74.934=0.437\ g$$