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: Research Ellipsoidal InAs Quantum Dots | Nanoscale Res Lett 2009 4 1256 DOI S11671-009-9371-1 NANO SPOTLIGHTS Ellipsoidal InAs Quantum Dots Published online 12 June 2009 to the authors 2009 Uses of semiconductor quantum dots QDs have been explored for attractive applications such as quantum information processing lasers and solar cells to name a few. However their ability to become integrated with existing technologies depends on shape composition and size all of which play a role in modifying both the optical and electrical properties of the QDs. However an in-depth understanding of the structure-property relationship of QDs is still lacking. In an effort to expand the understanding of this relationship scientists from the Radboud University Nijmegen The Netherlands Eindhoven University of Technology The Netherlands and the Ruhr-Universitat in Bochum Germany have employed the use of crosssectional scanning tunneling microscopy X-STM a technique perfected by Paul Koenraad s group at the COBRA Inter-University Research Institute in Eindhoven to investigate and determine the structural composition of InAs QDs. The results of the work entitled Ellipsoidal InAs quantum dots observed by cross-sectional scanning tunneling microscopy was published in Applied Physics Letters. We were surprised to find that the shape and composition deviate strongly from those which are usually used says Janneke Blokland PhD student at the Nijmegen High Field Magnet Laboratory HFML and first author of the paper. The dots have an ellipsoidal shape and turned out to be much taller and with a stronger indium gradient than expected . The report was very interesting since both the optical and electrical properties of the ellipsoidal QDs were earlier determined and reported in a Physical Review B paper Hole levels in InAs self-assembled quantum dots . This is the first time that structural and spectroscopic Size shape and composition of an In Ga As quantum dot. The percentages indicate the fraction of InAs and reveals that it .