Single-electron emission-injection transport in a microstructure with colloidal quantum dots of narrow-gap semiconductors

By approximating the tunneling current-voltage characteristics (CVCs) of colloidal quantum dots (QDs) of narrow-gap semiconductors InSb and PbS, it is shown that in the one-electron mode, electron transport is determined by competing processes – emission from a quantum dot, injection into it and transport through it with current limitation by space charge. At voltages above 0.5 V, for single QD on the CVCs, regions of instability and current dip similar to the Coulomb gap were observed. Qualitative and numerical comparative estimates suggest that one-electron transport and current limitation similar to the Coulomb blockade are observed in the structure of a segregated set of quantum dots. Illumination of the sample with white light when measuring the CVCs breaks the Coulomb blockade, greatly increasing or decreasing the current, depending on the spectrum of the exciting light.