ABSTRACT
We describe the fabrication of quantum wire (QWR) and quantum dot (QD) structures by metal-organic vapour phase epitaxial (MOVPE) growth, their characterization of optical and electronic properties and their application to quantum devices. Firstly, multiatomic steps formed during MOVPE growth on vicinal (001) GaAs surfaces were used to introduce lateral confinement potential and to realize QWRs. Based on the understanding of the formation process of GaAs and InGaAs multiatomic steps on vicinal (001) GaAs surfaces, InGaAs/GaAs QWRs were successfully fabricated on multiatomic steps and their one-dimensional nature was verified by comprehensive study of their optical properties. Application of QWRs to lasers was also demonstrated. Next, GaAs and InAs quantum dot and related nanostructures were fabricated by selective area (SA)-MOVPE growth. Zero-dimensional character of QDs formed by SA-MOVPE was demonstrated by the ultra-narrow PL peak from InAs QDs. Quantum dots connecting with GaAs quantum wires were also fabricated and they were applied to GaAs single electron transistors (SETs) and resistance-load single electron inverter circuit. Clear Coulomb blockade type conductance oscillations were observed near the pinch-off voltage of SETs at low temperatures. The inverter operation of a circuit using this SET together with load resistance was also demonstrated.
