Magnetotransport and Coulomb Blockade in Single InAs Colloidal Quantum Dot Transistors.

Abstract

Controlling and understanding carrier transport in colloidal quantum dots (CQDs) is crucial for device applications. However, owing to fluctuations in the sizes and morphologies of CQD arrays, characterizing carrier transport is challenging. In this study, we investigated carrier transport through a single oleic acid-capped Indium Arsenide (InAs) CQD coupled to nanogap metal electrodes. By measuring single-electron tunneling through individual CQDs, we characterized the dot size-dependent charging energy, bandgap energy, and spin-dependent electron transport. These measurements provide insight into the intrinsic electronic properties of InAs CQDs. Building on these measurements, we demonstrated room-temperature operation of single-electron transistors. Moreover, the observation of a large diamagnetic shift and Zeeman splitting enables magnetic-field control of orbital and spin states, demonstrating the potential of InAs CQDs for applications not only in optoelectronics but also in spintronics and quantum information devices.