Nanomaterials @ Interfaces Research Group

Chemical deposition of nanocrystalline PbS, CdS, and ZnS at the air/solution interface in the absence and presence of a polydiacetylene (PDA) Langmuir film is investigated in situ using grazing incidence X-ray diffraction. In all cases, it is found that PDA has a pronounced effect on the incipient semiconductor nanocrystals (NCs). In the presence of PDA, PbS NCs showed a 〈111〉 orientation in addition to the commonly obtained 〈100〉 growth direction of the PbS rock salt structure while CdS and ZnS NCs crystallized in the zinc blende polymorph with a predominant 〈100〉 orientation. ZnS NCs were obtained only in the presence of PDA at the air/solution interface.