Characteristics of InGaAs quantum dots grown on tensile-strained GaAs1-xPx.

Authors :: Kim, N. H.
Ramamurthy, P.
Mawst, L. J.
Kuech, T. F.
Modak, P.
Goodnough, T. J.
Forbes, D. V.
Kanskar, M.
Source :: Journal of Applied Physics; 5/1/2005, Vol. 97 Issue 9, p093518, 5p, 2 Black and White Photographs, 1 Diagram, 2 Charts, 6 Graphs
Publication Year :: 2005
Abstract: InGaAs quantum dots (QDs) embedded in tensile-strained GaAs<subscript>1-x</subscript>P<subscript>x</subscript> (x=0.0–0.45) barrier layers are grown using low-pressure metal-organic chemical-vapor deposition. Variable-temperature photoluminescence (PL) measurement demonstrates that the lowest-energy QD transition can be blueshifted up to 90 nm compared with similar structures utilizing GaAs barriers. Temperature-dependent PL measurements and atomic force microscopy surface imaging show that the InGaAs QDs grown on GaAsP exhibit reduced height, which is consistent with shorter-wavelength emission. Preliminary results from broad stripe (100 μm wide) diode lasers utilizing two stacks of InGaAs QDs embedded in GaAs<subscript>0.82</subscript>P<subscript>0.18</subscript> barriers exhibit a 30% reduction in threshold current density compared with similar laser structures which have GaAs barriers. [ABSTRACT FROM AUTHOR]