Abstract

A fundamentally new approach for synthesizing semiconductor nanocrystals—sizes-electively— is described in this talk. β-CuI and CdS nanocrystallites (NCs) have been synthesized on the atomically smooth graphite basal plane surface with use of a hybrid electrochemical/chemical (henceforth E/C) method. This method involves the following steps: 1) Electrochemical deposition of metal (e.g., Cu, Cd) NCs onto an electrode surface; 2) Electrochemical oxidation of these metal NCs to yield either an oxide or a hydroxide intermediate [e.g., Cu₂O, Cd(OH)₂]; and 3) Displacement of oxygen (or hydroxide) by iodide (or sulfide) in an aqueous KI (Na₂S) solution. The dispersions of nanocrystals generated by the E/C method possess the following characteristics: Single aystallinity, good-to-excellent size monodispersity, and epitaxial alignment (with the hexagonal periodicity of the graphite(0001) surface). In addition, E/C deposited particles on graphite exhibit strong room-temperature luminescence.

© 1997 Optical Society of America