Sequential Transport in a Two-Dot Device

A physical model of sequential transport through a device containing two semiconductor nanocrystals has been developed. It is based on (i) the calculation of the nanocrystal phonon modes, (ii) the self consistent calculation of the nanocrystal electronic structure including collisional broadening, (iii) the calculation of tunnelling rates and (iv) the Monte Carlo computation of sequential tunnel transfers. The obtained I-V curve takes the form of a narrow peak whose width decreases with decreasing temperature. Lateral peaks due to phonon-assisted tunnelling appear to be strongly influenced by the temperature and by the surface phonon modes in the dots.