Competition between carrier recombination and tunneling in quantum dots and rings under the action of electric fields

In the presence of a stationary electric field applied in the growth direction tunneling of electrons out of the quantum dots can take place. This mechanism competes with the quantum confined Stark effect (QCSE) that produces an increase of the exciton lifetime by increasing the electric field, mainly due to a net decrease of the electron-hole wavefunction overlap. The electric field range where QCSE dominates over tunneling will be mainly determined by the size of the nanostructure along the vertical direction (height), as demonstrated in this work.