Optical and microstructural studies of InGaN/GaN quantum dot ensembles

Davies, S. C.; Mowbray, D. J.; Ranalli, F.; Parbrook, P. J.; Wang, Q.; Wang, T.; Yea, B. S.; Sherliker, B. J.; Halsall, M. P.; Kashtiban, R. J.; Bangert, U.
September 2009
Applied Physics Letters;9/14/2009, Vol. 95 Issue 11, p111903
Academic Journal
An optical and structural study of InGaN/GaN quantum dots (QDs) is reported. With increasing InGaN deposition time, the dominant emission changes from wetting layer (WL) to QDs, and a strong redshift of the emission occurs. Emission from localized WL states is observed, with a density and nature very different to that due to the QDs. Structural measurements reveal a disordered WL, consistent with the form of the WL photoluminescence excitation spectra.


Related Articles

  • Morphology Of CdTe/ZnTe Self-Assembled Quantum Dots Studied By Excitation Spectroscopy. Nguyen, T. A.; Hoang, T. B.; Mackowski, S.; Jackson, H. E.; Smith, L. M.; Wrobel, J.; Fronc, K.; Kossut, J.; Karczewski, G. // AIP Conference Proceedings;2005, Vol. 772 Issue 1, p677 

    We perform photoluminescence excitation measurements on single CdTe quantum dots. The results demonstrate that multiple quantum dots can have identical sequences of excitation resonances. We attribute these resonances to electronic states within two-dimensional platelets that are formed prior to...

  • Highly uniform and strain-free GaAs quantum dots fabricated by filling of self-assembled nanoholes. Heyn, Ch.; Stemmann, A.; Köppen, T.; Strelow, Ch.; Kipp, T.; Grave, M.; Mendach, S.; Hansen, W. // Applied Physics Letters;5/4/2009, Vol. 94 Issue 18, p183113 

    We demonstrate the self-assembled creation of a novel type of strain-free semiconductor quantum dot (QD) by local droplet etching (LDE) with Al to form nanoholes in AlGaAs or AlAs surfaces and subsequent filling with GaAs. Since the holes are filled with a precisely defined filling level, we...

  • Hole spin relaxation in neutral InGaAs quantum dots: Decay to dark states. Hall, K. C.; Koerperick, E. J.; Boggess, Thomas F.; Shchekin, O. B.; Deppe, D. G. // Applied Physics Letters;1/29/2007, Vol. 90 Issue 5, p053109 

    The authors report measurements of hole spin relaxation in neutral InGaAs quantum dots using polarization-dependent time-resolved photoluminescence experiments. The single-particle hole spin relaxation was isolated from other spin flip processes in the electron-hole system by detecting the...

  • Room temperature optical gain in sol-gel derived CdS quantum dots. Butty, J.; Peyghambarian, N.; Kao, Y. H.; Mackenzie, J. D. // Applied Physics Letters;11/18/1996, Vol. 69 Issue 21, p3224 

    Under strong nanosecond excitation, we demonstrate that II–VI semiconductor quantum dots exhibit optical gain up to room temperature. The CdS nanocrystallites, fabricated by sol-gel process, are embedded in a sodium borosilicate glass matrix. The gain is spectrally broad and the crossing...

  • Theoretical simulation of carrier capture and relaxation rates in quantum-dot semiconductor optical amplifiers. Yunhu Wu; Guoping Zhang; Ling Guo; Xiaoming Li; Guoqun Qi // Journal of Applied Physics;2014, Vol. 115 Issue 22, p224502-1 

    Based on Auger scattering mechanism, carrier-carrier scattering dynamics between the twodimensional carrier reservoir (also called wetting layer, i.e., WL) and the confined quantum dot ground and first excited state in quantum-dot semiconductor optical amplifiers (QD-SOAs) are investigated...

  • Influence of alloy buffer and capping layers on InAs/GaAs quantum dot formation. Dasika, V. D.; Song, J. D.; Choi, W. J.; Cho, N. K.; Lee, J. I.; Goldman, R. S. // Applied Physics Letters;10/19/2009, Vol. 95 Issue 16, p163114 

    We have investigated the influence of alloy buffer and capping layers on the shape, size, and density of self-assembled InAs/GaAs quantum dots. Cross-sectional scanning tunneling microscopy (XSTM) images reveal ellipse-shaped dots with highest (lowest) diameter, height, and density, for dots...

  • Localized excitation of InGaAs quantum dots by utilizing a photonic crystal nanocavity. Nomura, Masahiro; Iwamoto, Satoshi; Nakaoka, Toshihiro; Ishida, Satomi; Arakawa, Yasuhiko // Applied Physics Letters;4/3/2006, Vol. 88 Issue 14, p141108 

    We have studied excitation wavelength dependence of light emission from InGaAs quantum dots (QDs) embedded in high-quality-factor photonic crystal nanocavities. The light emission of the cavity mode around 1 μm was very weak with below-band-gap excitation in the InGaAs wetting layer. However,...

  • High optical sensitivity to ambient conditions of uncapped InGaAs surface quantum dots. Milla, M. J.; Ulloa, J. M.; Guzmán, A. // Applied Physics Letters;3/26/2012, Vol. 100 Issue 13, p131601 

    The influence of the environment on the optical properties of self-assembled In0.5Ga0.5As surface quantum dots is studied as a function of different ambient conditions for sensing applications. Their room temperature photoluminescence (PL) quenches under vacuum and decreases strongly under dry...

  • Strain induced stabilization of stepped Si and Ge surfaces near (001). Shenoy, V. B.; Ciobanu, C. V.; Freund, L. B. // Applied Physics Letters;7/8/2002, Vol. 81 Issue 2, p364 

    We report on calculations of the formation energies of several [100] and [110] oriented step structures on biaxially stressed Si and Ge (001) surfaces. It is shown that a novel rebonded [100] oriented single-height step is strongly stabilized by compressive strain compared to most well-known...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics