Electronic properties of phosphorus donors in hydrogenated silicon nanocrystals are investigated using a real-space ab initio pseudopotential method for systems with up to 500 atoms. We present calculations for the ionization energy, binding energy, and electron density associated with the doped nanocrystal. We find that the ionization energy for the nanocrystal is virtually independent of size...

We introduce an ultrathin donor-acceptor solar cell composed entirely of inorganic nanocrystals spin-cast from solution. These devices are stable in air, and post-fabrication processing allows for power conversion efficiencies approaching 3% in initial tests. This demonstration elucidates a class of photovoltaic devices with potential for stable, low-cost power generation.

Nearly monodisperse alloyed (CuInS2)x(ZnS)1-x nanocrystals with cubic and hexagonal phases were successfully synthesized for the first time, and the band gaps of these alloyed nanocrystals can be tuned in the broad range of 1.5 to 3.7 eV by changing the ratio of CuInS2 to ZnS.

This short perspective describes recent developments in the synthesis of nanoscale colloids from sparingly soluble precursors. These strategies, which we dubbed 'heterogeneous nanocrystal syntheses' owing to the presence of a precursor in a non-colloidal solid state, have demonstrated the ability to generate new colloidal shapes, a superior monodispersity and a remarkable ability to delay the o...

CdSe nanocrystals in solution and films can enter a metastable state in which the highly luminescent nanocrystals become dark. This change, which we attribute to a surface transformation, can be caused by heating or by changing the environment of the nanocrystals at room temperature. The metastable transformation is reversed upon illumination of above-band-gap light, at which point the nanocrys...

Branched nanocrystal heterostructures synthesized from CdSe and CdTe exhibit a type II band structure alignment that induces separation of charge upon photoexcitation and localizes carriers to different regions of the tetrahedral geometry. The dynamics of carrier relaxation examined with femtosecond pump-probe spectroscopy showed heterostructures having rise times and biexponential decays longe...

We systematically explore the shape-dependent catalytic activities of Au nanocrystals toward glucose oxidation in alkaline electrolytes, which is strongly dependent on the shape of the Au nanocrystals. The {100}-bounded cubic Au nanocrystals are significantly more active than the {110}-bounded rhombic dodecahedral and {111}-bounded octahedral Au nanocrystals.

The structural, chemical and electronic changes of ceria as a function of decreasing particle size have been studied: at sizes below 5 nm the total amount of reducible oxygen dramatically increases due to superoxide formation on the ceria surface, a result indicative of a size dependent oxygen buffering capacity.