Density and size control of InP/GaInP quantum dots on GaAs substrate grown by gas source molecular beam epitaxy

Nanotechnology. 2012 Jan 13;23(1):015605. doi: 10.1088/0957-4484/23/1/015605. Epub 2011 Dec 8.

Abstract

We demonstrate a method to controllably reduce the density of self-assembled InP quantum dots (QDs) by cyclic deposition with growth interruptions. Varying the number of cycles enabled a reduction of the QD density from 7.4 × 10(10) cm(-2) to 1.8 × 10(9) cm(-2) for the same total amount of deposited InP. Simultaneously, a systematic increase of the QD size could be observed. Emission characteristics of different-sized InP QDs were analyzed. Excitation power dependent and time-resolved measurements confirm a transition from type I to type II band alignment for large InP quantum dots. Photon autocorrelation measurements of type I QDs performed under pulsed excitation reveal pronounced antibunching (g((2))(τ = 0) = 0.06 ± 0.03) as expected for a single-photon emitter. The described growth routine has great promise for the exploitation of InP QDs as quantum emitters.

Publication types

  • Research Support, Non-U.S. Gov't