Spatially directed electrosynthesis of semiconductors for photoelectrochemical applications

It is possible to spatially direct the electrosynthesis of semiconductors on targeted substrates. For example, Se islands on a titanium dioxide surface can serve as chemical templates for the subsequent photoassisted deposition of MSe (M = metal such as Cd, Zn, or Pb) on the oxide surface. The resultant MSe/TiO2 composites have many useful practical applications. The use of physical templates such as polystyrene spheres or anodized alumina is another strategy to secure spatially directed electrosynthesis of semiconductors. Finally, the combined use of e-beam lithography and electrosynthesis is illustrated. The interesting structures described in this article have applications in solar cells, sensors, environmental remediation, ‘smart’ windows/displays, and the like.