Strain and optical transitions in InAs quantum dots on (001) GaAs |
| |
| Institution: | 1. Physical Electronics and Photonics, Microtechnology Center at Chalmers, Department of Physics, Fysikgränd 3, Chalmers University of Technology and Gothenburg University, S-412 96 Göteborg, Sweden;2. Photonics Laboratory, Microtechnology Center at Chalmers, Department of Microelectronics ED, Chalmers University of Technology, S-412 96 Göteborg, Sweden;1. Universidad Autónoma de Puebla, Instituto de Física, Apartado Postal J-48, Puebla 72570, Mexico;2. Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apartado Postal 14, Ensenada Baja California, Código Postal 22800, Mexico;1. State Key Laboratory of Catalysis, CAS Center for Excellence in Nanoscience, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, Liaoning, China;2. University of Chinese Academy of Sciences, Beijing, 100049, China;1. Laboratoire de la Matière Condensée et des Sciences Interdisciplinaires (LaMCScI), Mohammed V University of Rabat, Faculty of Sciences, B.P. 1014 Rabat, Morocco;2. Intelligent Processing and Security Systems, Mohammed V University of Rabat, Faculty of Sciences, B.P. 1014 Rabat, Morocco;3. USM/DERS/Centre National de l’Energie, des Sciences et des Techniques Nucléaires (CNESTEN), Rabat, Morocco;1. Department of Electrical and Computer Engineering, Wayne State University, Detroit, MI 48202, USA;2. Division of Computer, Electrical, and Mathematical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-69100, Saudi Arabia |
| |
| Abstract: | To investigate the strain characteristics of InAs quantum dots grown on (001) GaAs by solid source molecular beam epitaxy we have compared calculated transition energies with those obtained from photoluminescence measurements. Atomic force microscopy shows the typical lateral size of the quantum dots as 20–22 nm with a height of 10–12 nm, and photoluminescence spectra show strong emission at 1.26 μ m when the sample is capped with a GaAs layer. The luminescence peak wavelength is red-shifted to 1.33 μ m when the dots are capped by an In0.4Ga0.6As layer. Excluding the strain it is shown that the theoretical expectation of the ground-state optical transition energy is only 0.566 eV (2.19 μ m), whereas a model with three-dimensionally-distributed strain results in a transition energy of 0.989 eV (1.25 μ m). It has thus been concluded that the InAs quantum dot is spatially strained. The InGaAs capping layer reduces the effective barrier height so that the transition energy becomes red-shifted. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
