Abstract
We have introduced ultra-low Al composition at the two-dimensional to three-dimensional transition stage of InAs/GaAs quantum dots (QDs) formation. Two main effects of AlAs on the QDs are revealed: one is to lower the nucleation barrier so as to reduce the critical nucleation thickness of QDs, which is demonstrated by a surface kinetic nucleation model. The other is to facilitate the In atoms migration from wetting layer (WL) to QDs, which holds some signatures such as both increased QDs density and size with increasing AlAs composition, as well as the peak energy red-shift of photoluminescence spectra. The enhanced In atoms migration from WL to QDs is further confirmed via photo-modulated reflectance experiments and energy band calculation, which both demonstrate the reduction of effective WL thickness after AlAs insertion. The observed effects of AlAs on QDs formation and growth evolution could be explained by the Al-alloying effects of InAs wetting layer.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
