pH dependant sticking probability of gold colloid on silicon

Gold nanoparticles from commercially available gold colloid were deposited onto a bare silicon substrate by the addition of an acid. The sticking probability of the gold nanoparticles onto the silicon is shown to be dependent on the pH and is maximised between a pH of 2 and 3 while not being significantly affected by the acid type or the colloid size. In addition, the aggregation of the nanoparticles is minimised when the sticking probability is maximised. This indicates optimal deposition conditions for high density deposition of monodispersed gold nanoparticles onto silicon for vapour–liquid–solid nanowire growth.