ISBN 9783843911412

978-3-8439-1141-2, Reihe Physik

Moritz Bommer
InP/(Al,Ga)InP Quantum Dots on GaAs- and Si-Substrates for Single-Photon Generation at Elevated Temperatures

194 Seiten, Dissertation Universität Stuttgart (2012), Hardcover, A5

Zusammenfassung / Abstract

This work concentrates on optical investigation on single-photon generation for applications in communications, quantum cryptography, and quantum computing. Single-photon sources for commercial devices require robustness in their working conditions, e.g. temperature, pressure, etc. as well as high output rates and emission directionality.

From the many possibilities of generating single-photons like single-atoms, parametric down-conversion, nitrogen vacancy centers in diamond etc., InP quantum dots have been chosen for detailed analysis in this thesis. The InP and InAs quantum dots discussed in this work, are epitaxially fabricated by MOVPE in the Stranski-Krastanov growth-mode.

The quantum dots have been fabricated on different substrates, namely miscut and exactly oriented GaAs, Si, and Ge virtual substrate on Si. The latter two might allow complementary metal oxide semiconductor (CMOS)-compatibility, which is of high interest because it allows the integration of optical elements into the commercially well established Si based environment. The main focus of this work lies on optical measurements of single quantum dots.

Extending the temperature range for InP quantum dots based single-photon sources from the current maximum temperature of 80K towards the regime of Peltier-cooling (≥ 150 K) is very desirable, because it reduces the footprint of a device and its servicing costs drastically. In this work, an enhancement of the working temperature up to 110 K has been shown.