tailieunhanh - Báo cáo hóa học: " Temperature dependent optical properties of single, hierarchically self-assembled GaAs/AlGaAs quantum dots"

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: Temperature dependent optical properties of single, hierarchically self-assembled GaAs/AlGaAs quantum dots | Nanoscale Res Lett 2006 1 172-176 DOI S11671-006-9019-3 ORIGINAL PAPER Temperature dependent optical properties of single hierarchically self-assembled GaAs AlGaAs quantum dots M. Benyoucef A. Rastelli O. G. Schmidt S. M. Ulrich P. Michler Published online 27 September 2006 to the authors 2006 Abstract We report on the experimental observation of bright photoluminescence emission at room temperature from single unstrained GaAs quantum dots QDs . The linewidth of a single-QD ground-state emission meV is comparable to the ensemble inhomogeneous broadening meV . At low temperature T 40 K photon correlation measurements under continuous wave excitation show nearly perfect single-photon emission from a single GaAs QD and reveal the single photon nature of the emitted light up to 77 K. The QD emission energies homogeneous linewidths and the thermally activated behavior as a function of temperature are discussed. Keywords GaAs quantum dots Hierarchical selfassembly Single dot spectroscopy Room temperature luminescence Photon correlation PACS numbers During the last decade much attention has been paid to the fabrication of semiconductor quantum dots QDs and to their optical properties. QDs have large oscillator strengths narrow spectral linewidths longterm stability and can be easily integrated inside device structures . pillar microcavities 1-4 . Single photon generation using single self-assembled QDs M. Benyoucef El A. Rastelli O. G. Schmidt Max-Planck-Institut fur Festkorperforschung Heisenbergstrasse 1 D-70569 Stuttgart Germany e-mail S. M. Ulrich P. Michler 5. Physikalisches Institut Universitat Stuttgart Pfaffenwaldring 57 D-70550 Stuttgart Germany obtained by Stranski-Krastanow SK growth mode has been demonstrated at low temperature 5 6 . Single photons are useful for applications in quantum cryptography and quantum computation. Understanding the temperature dependence of QD emission is essential