화학공학소재연구정보센터
Journal of Crystal Growth, Vol.370, 303-306, 2013
Graded GaAsSb strain reducing layers covering InAs/GaAs quantum dots
We have grown new InAs/GaAs quantum dot (QD) structures with graded Sb concentration of GaAs(1-x)Sbx strain reducing layer (SRL). New types of GaAsSb SRLs with graded concentration of Sb are theoretically and experimentally studied. We compare properties of three different Sb concentration gradients in SRL, constant, increasing and decreasing during the growth. Both types of non-constant gradients help us to prevent transition of the InAs(QD)/GaAsSb(SRL) heterojunction from type I to type II, to increase emission wavelength and to retain high luminescence intensity of these types of QD structures. Comparison of photoluminescence of samples with different concentration gradients and similar average Sb concentration in SRLs is shown. The longest wavelength of type I ground state transition was achieved on sample with decreasing gradation of Sb content in SRL-1399 nm (0.886 eV). (C) 2012 Elsevier B.V. All rights reserved.