tailieunhanh - Báo cáo hóa học: " A study of nitrogen incorporation in pyramidal site-controlled quantum dots"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : A study of nitrogen incorporation in pyramidal site-controlled quantum dots | Juska et al. Nanoscale Research Letters 2011 6 567 http content 6 1 567 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access A study of nitrogen incorporation in pyramidal site-controlled quantum dots Gediminas Juska Valeria Dimastrodonato Lorenzo O Mereni Agnieszka Gocalinska and Emanuele Pelucchi Abstract We present the results of a study of nitrogen incorporation in metalorganic-vapour-phase epitaxy-grown site-controlled quantum dots QDs . We report for the first time on a significant incorporation approximately producing a noteworthy red shift at least 50 meV in some of our samples. Depending on the level of nitrogen incorporation exposure strong modifications of the optical features are found variable distribution of the emission homogeneity fine-structure splitting few-particle effects . We discuss our results especially in relation to a specific reproducible sample which has noticeable features the usual pattern of the excitonic transitions is altered and the fine-structure splitting is suppressed to vanishing values. Distinctively nitrogen incorporation can be achieved without detriment to the optical quality as confirmed by narrow linewidths and photon correlation spectroscopy. Keywords MOVPE site-controlled quantum dots dilute nitride semiconductors Background Quantum dots QDs are usually referred to as artificial atoms due to the discrete nature of energetic structure and similarities in quantum properties. Application of individual QDs is envisioned in the fields of advanced optoelectronics photonics quantum information processing 1 . Among the properties required to be met are certainly precise control over positioning . inside a photonic cavity or waveguide high optical quality . low or absent spectral meandering of the excitonic features and high uniformity as a guarantee of technological scalability. In many respects features like tailored symmetry properties . better than C2v for .