Controllable Growth of Semiconductor Heterostructures Mediated by Bifunctional Ag2S Nanocrystals as Catalyst or Source-Host

Abstract

We demonstrate that Ag₂S nanocrystals are the bifunctional mediator for controllable growth of semiconductor heterostructures including more complicated multisegments heterostructures in solution-phase, which is a new type of nanomediator and quite different from the metal nanoparticle catalyst. The intrinsic high Ag⁺ ion mobility makes Ag₂S nanocrystals not only exhibit excellent catalytic function for growth of metal sulfide heterostructures but also act as a source-host for growth of ternary semiconductor heterostructures, for example, Ag₂S-AgInS₂. The semiconductors grow epitaxially from or inward in Ag₂S nanocrystals forming single-crystalline heterostructures. Moreover, the method developed here also can construct multisegments heterostructures, for example, Ag₂S-CdS-ZnS, AgInS₂-Ag₂S-AgInS₂. The interfacial structure is still stable even if the lattice mismatch is quite large, which is a unique feature of this method.