Explain why arsenic-doped silicon conducts electric current better than pure silicon?

Answer 1

Pure silicon is intrinsic. It has a high resitivity which means it is a poor conductor of electricity in this state. The dopant that is introduced during the doping process can be arsenic, boron or phosphorous. These are the traditional choices to dope the intrinsically pure silicon. After the pure silicon becomes doped its electrical properties change. The main change is it has a lower resistivity and will conduct electricity. This is why silicon is called a semiconductor.