COMBINATORIAL APPROACHES TOWARD PATTERNING NANOCRYSTALS

A scheme for generating complex, spatially separated patterns of multi ple types of semiconducting and/or metallic nanocrystals is presented. The process is based on lithographic patterning of organic monolayers that contain a photolabile protection group and are covalently bound to SiO2 surfaces. The process results in spatially and chemically dist inct interaction sites on a single substrate. Nanocrystal assembly occ urs with a high selectivity on just one type of site. We report on the production of binary, tertiary, and quaternary patterns of nanocrysta ls. We highlight and discuss the differences between nanocrystal/subst rate assembly and molecule/substrate assembly. Finally, we investigate the assembled structures using photoluminescence and absorption spect roscopy. (C) 1998 American Institute of Physics. [S0021-8979(98)06719- X]