Small Is Different:  Shape-, Size-, and Composition-Dependent Properties of Some Colloidal Semiconductor Nanocrystals

Abstract

As the size of material becomes equal to or falls below the nanometer length scale that characterizes the motion of its electrons and thus its properties, the latter become sensitive not only to the size but also to the shape and composition of the particles. In this Account, we describe the changes of some interesting properties in different colloidal semiconductor nanoparticles, such as the electronic relaxation rates as spherical nanoparticles change to nanorods, and the changes in the structure or size of very small nanoparticles upon adsorbing strongly bound molecules. We have also determined and explained the difference in the interfacial crossing rates of electrons and holes in a composite nanostructure.

One-pot sonochemical synthesis of CdS nanoparticles: photocatalytic and electrical properties

“…For nanoparticles prepared by solution-based chemical methods, a capping agent, which adsorbs on to the nanoparticle surface, is generally added both to control the size of the nanoparticles and to prevent agglomeration of the synthesized particles. These adsorbents have been shown to alter the electronic structure of the nanoparticles [10,11].…”

Fluxionality of gold nanoparticles investigated by Born-Oppenheimer molecular dynamics

“…In particular the chemistry of small gold particles has attracted much attention and its theoretical properties have been extensively reviewed [4][5][6][7]. Such interest originates from several reasons: the special catalytic activity of small clusters as compared to larger ones [8][9][10], possible application in the building of nanoscale devices [11][12][13], the special properties as semiconductors [14,15], biosensors [16], electrodes [17] and their optical properties [16,18,19]. In general when the dimensions of metal particles are reduced to a size comparable to that of the constituent atoms, their electronic structure deviates dramatically from that of the bulk metal.…”

Surface modification-induced phase transformation of hexagonal close-packed gold square sheets

“…The functional properties of inorganic nanocrystals can be tuned by controlling their size, shape, composition and topology 3,4 . In addition, the crystal phase of inorganic nanomaterials can also strongly affect their properties, such as magnetic 5,6 , optical 7 , catalytic 8 and electrical properties 9 .…”