Strain-Tunable Quantum Dot Devices

Abstract

We introduce a new class of quantum dot-based devices, in which the semiconductor structures are integrated on top of piezoelectric actuators. This combination allows on one hand to study in detail the effects produced by variable strains (up to about 0.2%) on the excitonic emission of single quantum dots and on the other to manipulate their electronic- and optical properties to achieve specific requirements. In fact, by combining strain with electric fields we are able to obtain (i) independent control of emission energy and charge-state of a QD, (ii) wavelength-tunable single-QD light-emitting diodes and (iii) frequency-stabilized sources of single photons at predefined wavelengths. Possible future extensions and applications of this technology will be discussed.