RESUMEN
Field-effect transistors (FETs) fabricated from undoped and Co(2+)-doped CdSe colloidal nanowires show typical n-channel transistor behaviour with gate effect. Exposed to microscope light, a 10 times current enhancement is observed in the doped nanowire-based devices due to the significant modification of the electronic structure of CdSe nanowires induced by Co(2+)-doping, which is revealed by theoretical calculations from spin-polarized plane-wave density functional theory.
Asunto(s)
Magnetismo , Nanocables/química , Semiconductores , Compuestos de Cadmio/química , Cobalto/química , Coloides/química , Oro/química , Compuestos de Selenio/química , Dióxido de Silicio/químicaRESUMEN
Co(2+)-doped CdSe colloidal nanowires with tunable size and dopant concentration have been prepared by a solution-liquid-solid (SLS) approach for the first time. These doped nanowires exhibit anomalous photoluminescence temperature dependence in comparison with undoped nanowires.
Asunto(s)
Compuestos de Cadmio/química , Cobalto/química , Nanocables/química , Compuestos de Selenio/química , Coloides/química , Semiconductores , Espectrometría de Fluorescencia , TemperaturaRESUMEN
The structures and thermodynamic properties of methyl derivatives of ammonia-borane (BH3NH3, AB) have been studied with the frameworks of density functional theory and second-order Møller-Plesset perturbation theory. It is found that, with respect to pure, methyl ammonia-boranes show higher complexation energies and lower reaction enthalpies for the release of H2, together with a slight increment of the activation barrier. These results indicate that the methyl substitution can enhance the reversibility of the system and prevent the formation of BH3/NH3, but no enhancement of the release rate of H2 can be expected.
