An approach to electrical studies of single nanocrystals

We present electrical measurements of single Au and CdSe nanocrystals. The devices are fabricated using a hybrid scheme which combines electron beam lithography and wet chemistry to bind nanocrystals in tunneling contact between two closely spaced metallic leads. The current–voltage characteristics of these devices exhibit a Coulomb staircase with a charging energy of ∼50 meV. This technique is readily adapted to the study of a host of nanocrystals made by solution chemistry.