tailieunhanh - Báo cáo hóa học: " Interaction and Cooperative Nucleation of InAsSbP Quantum Dots and Pits on InAs(100) Substrate"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Interaction and Cooperative Nucleation of InAsSbP Quantum Dots and Pits on InAs(100) Substrate | Nanoscale Res Lett 2010 5 587-591 DOI s11671-009-9510-8 NANO EXPRESS Interaction and Cooperative Nucleation of InAsSbP Quantum Dots and Pits on InAs 100 Substrate Karen M. Gambaryan Received 19 November 2009 Accepted 9 December 2009 Published online 24 December 2009 The Author s 2009. This article is published with open access at Abstract An example of InAsSbP quaternary quantum dots QDs pits and dots-pits cooperative structures growth on InAs 100 substrates by liquid phase epitaxy LPE is reported. The interaction and surface morphology of the dots-pits combinations are investigated by the high-resolution scanning electron microscope. Bimodal growth mechanism for the both QDs and pits nucleation is observed. Cooperative structures consist of the QDs banded by pits as well as the large pits banded by the quantum wires are detected. The composition of the islands and the pits edges is found to be quaternary enriched by antimony and phosphorus respectively. This repartition is caused by dissociation of the wetting layer followed by migration surface diffusion of the Sb and P atoms in opposite directions. The small QDs average density ranges from to 2 X 109 cm-2 with heights and widths dimensions from 2 to 20 nm and 5 to 45 nm respectively. The average density of the small pits is equal to 6-10 X 109 cm-2 with dimensions of 5-40 nm in width and depth. Lifshits-Sle-zov-like distribution for the amount and surface density of both small QDs and pits versus their average diameter is experimentally detected. A displacement of the absorption edge toward the long wavelength region and enlargement toward the short wavelength region is detected by the Fourier transform infrared spectrometry. Keywords Quantum dots Pits Liquid phase epitaxy Strain-induced III-V compound semiconductors K. M. Gambaryan El Department of Physics of Semiconductors and Microelectronics Yerevan State University 1 A. Manoukian Str. Yerevan 0025 Armenia e-mail .