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تسجيل مستخدم جديدتحليل خطي لنظام النقاط الكمية المجمعة تلقائيا بشكل الإبتاعي
Order of Epitaxial Self-Assembled Quantum Dots: Linear Analysis
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تأليف
Lawrence H. Friedman
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تتأثر النقاط الكمية المجمعة تلقائياً الإبتاعية (SAQDs) بالإهتمام للأجهزة الإلكترونية والإشعاعية المنحنية الصغيرة مثل الليزرات ومستشعرات الضوء والمنطق الصغير الحجم. النظام المكاني والنظام الحجمي للنقاط الكمية المجمعة تلقائياً هما مهمان لتطوير الأجهزة القابلة للاستخدام. من المحتمل أن هذين النوعين من النظام يرتبطان بشدة؛ لذلك، يشكل الدراسة المكانية أيضاً تأثيراً قوياً على النظام الحجمي. يتم هنا الدراسة المكانية باستخدام تحليل خطي لنموذج معتاد لإنشاء النقاط الكمية المجمعة تلقائياً بناء على التحرك السطحي. وتتم العثور على صيغ الجمع الحسابية لوظائف الارتفاع الأفلام التي تشخص النظام المكاني للنقاط الكمية وأطوال الارتباط المقابلة التي تقييم النظام. وتؤدي الانحرافات الأولية الذاتية الحجم الذري إلى أطوال ارتباط قليلة جداً (حوالي نقطتين) عندما يكون تأثير الجذب الرطوبة صفراً؛ ومع ذلك، تؤدي الأطوال الارتباط إلى الانحراف عندما يسمح لإنشاء SAQDs في ارتفاع أفلام قريب من الحالة الحرارية النقطية. يعزز هذا العمل النتائج السابقة حول البعدية والنظام SAQD ويقدم محركاً واضحاً ومحسناً للترتيب مع المعادلات التحليلية المقابلة. بالإضافة إلى ذلك، فإن إنشاء SAQD يعتبر عملية استثنائية بطبيعتها، ويتم عرض الجوانب الرياضية المختلفة حول التحليل الإحصائي لإنشاء SAQD والنظام.
Epitaxial self-assembled quantum dots (SAQDs) are of interest for nanostructured optoelectronic and electronic devices such as lasers, photodetectors and nanoscale logic. Spatial order and size order of SAQDs are important to the development of usable devices. It is likely that these two types of order are strongly linked; thus, a study of spatial order will also have strong implications for size order. Here a study of spatial order is undertaken using a linear analysis of a commonly used model of SAQD formation based on surface diffusion. Analytic formulas for film-height correlation functions are found that characterize quantum dot spatial order and corresponding correlation lengths that quantify order. Initial atomic-scale random fluctuations result in relatively small correlation lengths (about two dots) when the effect of a wetting potential is negligible; however, the correlation lengths diverge when SAQDs are allowed to form at a near-critical film height. The present work reinforces previous findings about anisotropy and SAQD order and presents as explicit and transparent mechanism for ordering with corresponding analytic equations. In addition, SAQD formation is by its nature a stochastic process, and various mathematical aspects regarding statistical analysis of SAQD formation and order are presented.
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