Charge transport in mixed CdSe and CdTe colloidal nanocrystal films

We report the influence of trap states on charge transport through films of mixed CdTe and CdSe nanocrystals (cid:1) NCs (cid:2) between lateral electrodes, through layered films of CdTe and CdSe NCs in a layered geometry, and through films of CdTe/CdSe nanobarbells in a layered geometry. We find that an electron trapping state on the surface of the CdTe NCs dominates the conduction in all devices studied. X-ray photoelectron spectroscopy and thermal activation studies implicate unpassivated or oxidized Te as the electron-trapping site.