Selective control of self-organized In0.5Ga0.5As/GaAs quantum dot properties: Quantum dot intermixing

Abstract

Selective postgrowth control of the photoluminescence ͑PL͒ wavelength has been demonstrated for a single layer self-organized In 0.5 Ga 0.5 As/GaAs quantum dot ͑QD͒ structure. This was achieved by rapid thermal processing of dots using different dielectric caps. Selective band gap shifts of over 100 meV were obtained between samples capped with sputtered and plasma enhanced silica deposition, with the band gap shift under regions covered with plasma enhanced chemical vapor deposition SiO 2 less than 70 meV. The effects of different caps on the PL linewidth were also observed. The differential band gap shift will enable the integration of passive and active devices in QD systems.

Post-growth thermal treatment of self-assembled InAs/GaAs quantum dots

“…Introduction published just recently [12,13]. In this paper, the results of the effect of RTA on InAs/GaAs QDs with GaAs One of the ways of tuning the properties of semiconproximity capping are presented and discussed [17].…”

“…In this paper, the results of the effect of RTA on InAs/GaAs QDs with GaAs One of the ways of tuning the properties of semiconproximity capping are presented and discussed [17]. ductor quantum dots (QDs) [1,2] is their postgrowth thermal treatment [3][4][5][6][7][8][9][10][11][12][13][14][15]. The postgrowth annealing is 2.…”

“…The structure investigated was grown by metaloorganrapid thermal annealing (RTA) system with Si0 2 capic vapor phase epitaxy in the Institute of Experimental ping [5,9,[12][13][14] or proximity capping, (which means ic v arpas epity The Gnstiut e oEx erieal an annealing with a piece of GaAs substrate in close Physics, Warsaw University. The GaAs buffer layer was proximity to the sample surface) [3,6,7].…”

InAs/GaAs quantum-dot intermixing: comparison of various dielectric encapsulants

“…This implies IFVD facilitated Ga vacancies started to promote intermixing right from low-annealing temperatures. 9 In addition, the PL intensity improvement (Table 1) and decrease in the PL linewidth [ Fig. 2(c)] is noted, which is ascribed to the improved dot size homogeneity and reduction in the grown-in-defects due to low-temperature growth of QDs.…”

“…This is found to promote (when GaAs surface is compressively strained) or trap (when GaAs surface is tensile strained) the V III at the interface, thus significantly affecting the intermixing process. 9,19,25,26 As the IFVD process is essentially impurity-free, the optical loss and degradation of electrical properties resulted from extended defect and free-carrier absorptions from impurity ions can be minimized to a great extent.…”