New physics and devices based on self-assembled semiconductor quantum dots

Abstract

Self-assembled semiconductor quantum dots (QDs) exhibit fully quantized electronic states and high radiative efficiencies. This makes them highly suitable both for fundamental physics studies of zero-dimensionality, atomic-like semiconductor systems and applications in a range of novel electro-optical devices. This review discusses recent important advances in the study and application of semiconductor QDs. Using a wide range of optical spectroscopy techniques, it is possible to obtain a detailed understanding of the electronic structure and dynamical carrier processes. Such an understanding is required for the implementation of a wide range of QD-based devices.

Granular electronic systems

“…Applications range from light emitting devices to photovoltaic cells and bio-sensors. The intense interest is motivated not only by the important technological promise but by the appeal of dealing with the experimentally accessible model system that is governed by tunable cooperative effects of disorder, electron correlations, and quantum phenomena (Gaponenko, 1998;Mowbray and Skolnick, 2005;Murray et al, 1993).…”

“…For the prototype system of InAs on GaAs, where the lattice mismatch is 7%, InAs initially deposited on GaAs grows as a strained two-dimensional layer (referred to as the wetting layer) (Mowbray and Skolnick, 2005). These materials along with In 2 O 3 : Sn (known as indium tin oxide, ITO) are the most widely studied systems.…”

Subthreshold diode characteristics of InAs/GaAs quantum dot lasers

“…InAs/GaAs quantum dots (QD) have received much attention for their potential use in next-generation telecoms light sources [1]. QD-based lasers were predicted to have low, temperature-insensitive threshold currents [2,3] but this requires large energy separations between the discrete QD states to suppress thermal effects.…”

Capping of InAs/GaAs Quantum Dots for GaAs Based Lasers

“…Nowadays, self-assembled InAs quantum dots grown on GaAs substrates are intensively studied due to their potential applications: quantum dot ensembles are employed in laser active regions and mid-infrared detectors, single quantum dots have a potential for application in memories, two-level information processing or single photon sources (Henini& Bugajski, 2005;Mowbray& Skolnick, 2005;Battacharya, 2007).…”