Splitting of the energy spectrum of an indirect exciton upon electron tunnelling between nanoparticles

We report an analytical study of the splitting of the energy spectrum of an electron for a quasi-two-dimensional indirect exciton (Q2D-IX) localised at the 'dielectric nanoparticle – dielectric medium' interface. The splitting results from electron tunnelling through a potential barrier separating neighbouring nanoparticles. The obtained expressions determine the energy and spatial parameters of the probability of electron tunnelling and the value of the energy splitting. It is found that tunnelling is possible under rigid conditions for the spatial parameters of the nanosystem and the ratio of the energies of the excited and ground exciton states. Tunnelling-induced splitting of the electron energy can reach 0.1 eV for some dielectric structures. This allows the impact of charge tunnelling on the energy spectrum of Q2D-IX systems to be predicted.