论文信息 - GaN/AlGaN nanocavities with AlN/GaN Bragg reflectors grown in AlGaN nanocolumns by plasma assisted MBE

GaN/AlGaN nanocavities with AlN/GaN Bragg reflectors grown in AlGaN nanocolumns by plasma assisted MBE

The successful growth of AlGaN nanocolumns by plasma assisted MBE, with different Al compositions, opened the way for achieving nano-heterostructures including GaN Quantum Discs (QDss). The luminescence emission from the QDss embedded in the AlGaN nanocolumns was tuned by changing their thickness and/or the Al composition of the barriers. Such a nano-heterostructure was then enclosed between two AlN/GaN Distributed Bragg Reflectors (DBR), with nominal reflectivities of 90 and 50%. The choice of the AlN/GaN bilayers for the DBRs allowed to reach these reflectivity values with a significantly lower number of periods, as compared to the AlGaN/GaN stacks. The resulting nanocavity has been characterized by cathodoluminescence (CL), and Scanning and Transmission Electron Microscopy (SEM, TEM). CL measurements show that the emission from the nanocavity is quite close to the targeted value. TEM data points to the need of optimized conditions to grow AlN columnar layers in order to avoid the lateral overgrowth in the columnar nanostructure.

[1] Achim Trampert,et al. Characterization of GaN quantum discs embedded in Al x Ga 1 − x N nanocolumns grown by molecular beam epitaxy , 2003 .

[2] P. Kozodoy,et al. Bias dependent microwave performance of AlGaN/GaN MODFET's up to 100 V , 1997, IEEE Electron Device Letters.

[3] M. Yoshizawa,et al. Self-organization of GaN/Al0.18Ga0.82N multi-layer nano-columns on (0 0 0 1) Al2O3 by RF molecular beam epitaxy for fabricating GaN quantum disks , 1998 .

[4] J. Baumberg,et al. Tunable resonant optical microcavities by self-assembled templating. , 2004, Optics letters.

[5] D. Čiplys,et al. Diffraction of guided optical waves by surface acoustic waves in GaN , 2000 .

[6] H. Sakaki,et al. Multidimensional quantum well laser and temperature dependence of its threshold current , 1982 .

[7] J. Ristić,et al. AlGaN Nanocolumns Grown by Molecular Beam Epitaxy: Optical and Structural Characterization , 2002 .

[8] Costas Fotakis,et al. LASERS, OPTICS, AND OPTOELECTRONICS 2865 Single-mode solid-state single photon source based on isolated quantum dots in pillar microcavities , 2001 .

[9] Shuji Nakamura,et al. GaN Growth Using GaN Buffer Layer , 1991 .

[10] F. Calle,et al. Luminescence properties and defects in GaN nanocolumns grown by molecular beam epitaxy , 2000 .

[11] MBE-grown high-quality (Al, Ga)N/GaN distributed Bragg reflectors for resonant cavity LEDs , 2001 .