The fabrication of self-catalyzed InP nanowires (NWs) is investigated under different growth conditions.Indium droplets induced by surface reconstruction act as nucleation sites for NW growth.Vertical standing NWs with uniform cross sections are obtained under optimized conditions.It is confirmed that the growth rate of NWs is strongly affected by the surface diffusion adatoms while contributions from the direct impingement of vapor species onto the In droplets can be negligible.The results indicate that the droplet acts as an adatom collector rather than a catalyst.Moreover,the diffusion flow rate of adatoms increases with time at the beginning of growth and stabilizes as the growth proceeds.