Nanomaterials @ Interfaces Research Group

Highly oriented arrays of lead sulfide (PbS) nanocrystals have been prepared in ambient conditions by the exposure of crystalline polydiacetylene (PDA) Langmuir films to H₂S gas at the air-PbCl₂ solution interface. The nanocrystals were studied by transmission electron microscopy (TEM), electron diffraction (ED), dark field TEM imaging (DF), high resolution TEM (HRTEM) and fast Fourier transform (FFT) analysis of HRTEM images. Three distinct, coexisting orientations were observed with typical nanocrystal morphologies corresponding to each orientation. The 〈110〉_pbs direction was aligned parallel to the PDA linear direction for all orientations, indicating a template-directed growth for the PbS/PDA system.