For n-type doping of A3B5 semiconductors silicon are commonly used. However, Si in A3B5 nanowire is p-type dopant. Species are incorporated into nanowire through the intermediate liquid phase. Solubility of metals in catalyst are usually much more than nitrogen family elements. Nitrogen family elements easily dissolve in metal carbon family elements such as lead and tin. Here we discuss the growth of GaAs nanowires with lead catalyst on Si substrate. Lead could easily dissolve nitrogen family elements as well as boron family elements, which allows to switch nanowire growth from metal-rich to pnictide-rich growth.