Transition metal substitution for H in graphane: a high-throughput study.

This systematic study of transition metal (TM) substitution for H on graphane TM H C, (TM  =  Sc, Ti, V, Cr, Mn) combines ab initio calculations and cluster expansion to explore a huge variety of structures in more than 20 supercells over the full concentration range from x  =  0 to 1. We find energetically favorable structures at each concentration in supercells not studied before. At low x the lowest-energy structures contain lines and bands of TM atoms.

Spatial distribution of electron densities during optical excitation of C60.

We calculate the spatial distribution of the oscillating electron density for the low energy optical excitations in C(60), using ab initio time-dependent density functional theory. We contrast this with the unscreened free response of the Kohn-Sham eigenfunctions, in which the charge transfer is between hemispheres and the simple density oscillation patterns are very similar for electrons outside and inside the C(60) radius. In the screened case, the oscillation patterns involve charge transfer on the scale of interatomic distances.

Synthesis and characterization of photoluminescent In-doped CdSe nanoparticles.

Indium-doped CdSe nanoparticles have been synthesized and characterized. Their light absorption, photoluminescence, and structure are similar to undoped CdSe nanoparticles. The greater part of the In associated with the nanoparticles is removed when the nanoparticles undergo ligand exchange by pyridine.

Surface transformation and photoinduced recovery in CdSe nanocrystals.

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 nanocrystals are again highly luminescent.