• A. F. Jarjour, A. M. Green, T. J. Parker, R. A. Taylor, R. A. Oliver, G. A. D. Briggs, M. J. Kappers, C. J. Humphreys, R. W. Martin, and I. M. Watson, “Two-photon absorption from single InGaN/GaN quantum dots,” Physica E: Low-dimensional Systems and Nanostructures, vol. 32, iss. 1-2, p. 119–122, 2006.
    [BibTeX] [Abstract] [Download PDF]

    We present a study of the time-integrated and time-resolved photoluminescence properties of single-InGaN/GaN quantum dots (QDs) using two-photon spectroscopy. Two samples containing QDs produced by different growth techniques are examined. We find that two-photon excitation results in the suppression of the emission from the underlying quantum well to which the QDs are coupled and yet relatively strong QD emission is observed. This effect is explained in terms of the enhancement of two-photon absorption in QDs due to the full confinement of carriers. Furthermore, evidence of the presence of excited states is revealed from the two-photon photoluminescence excitation spectra presented in the study.

    @article{strathprints10020,
    volume = {32},
    number = {1-2},
    title = {Two-photon absorption from single InGaN/GaN quantum dots},
    author = {A.F. Jarjour and A.M. Green and T.J. Parker and R.A. Taylor and R.A. Oliver and G.A.D. Briggs and M.J. Kappers and C.J. Humphreys and R.W. Martin and I.M. Watson},
    year = {2006},
    pages = {119--122},
    journal = {Physica E: Low-dimensional Systems and Nanostructures},
    keywords = {InGaN, quantum dot, two-photon absorption, photoluminescence, time-resolved, photoluminescence excitation, Physics, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Condensed Matter Physics},
    url = {http://strathprints.strath.ac.uk/10020/},
    abstract = {We present a study of the time-integrated and time-resolved photoluminescence properties of single-InGaN/GaN quantum dots (QDs) using two-photon spectroscopy. Two samples containing QDs produced by different growth techniques are examined. We find that two-photon excitation results in the suppression of the emission from the underlying quantum well to which the QDs are coupled and yet relatively strong QD emission is observed. This effect is explained in terms of the enhancement of two-photon absorption in QDs due to the full confinement of carriers. Furthermore, evidence of the presence of excited states is revealed from the two-photon photoluminescence excitation spectra presented in the study.}
    }

  • A. F. Jarjour, R. A. Taylor, R. W. Martin, and I. M. Watson, “Two-photon absorption in site-controlled InGaN/GaN quantum dots,” Physica Status Solidi C, vol. 2, iss. 11, p. 3843–3846, 2005.
    [BibTeX] [Abstract] [Download PDF]

    We present micro-photoluminescence measurements on single site-controlled InGaN/GaN quantum dots using two-photon excitation Furthermore, measurements of photoluminescence excitation and time-resolved photoluminescence are also presented. We show that two-photon excitation results in total suppression of the emission from the underlying quantum well, to which the quantum dots are couple, and yet strong quantum dot emission. We attribute this effect to the enhancement of the two-photon absorption in the quantum dots as a result of the zero-dimensional confinement compared to that of the quantum wells.

    @article{strathprints9983,
    volume = {2},
    number = {11},
    month = {November},
    author = {A.F. Jarjour and R.A. Taylor and R.W. Martin and I.M. Watson},
    title = {Two-photon absorption in site-controlled InGaN/GaN quantum dots},
    journal = {Physica Status Solidi C},
    pages = {3843--3846},
    year = {2005},
    keywords = {42.65.?k, 78.67.Hc, 78.47.+p;78.55.Cr, Physics, Condensed Matter Physics},
    url = {http://strathprints.strath.ac.uk/9983/},
    abstract = {We present micro-photoluminescence measurements on single site-controlled InGaN/GaN quantum dots using two-photon excitation Furthermore, measurements of photoluminescence excitation and time-resolved photoluminescence are also presented. We show that two-photon excitation results in total suppression of the emission from the underlying quantum well, to which the quantum dots are couple, and yet strong quantum dot emission. We attribute this effect to the enhancement of the two-photon absorption in the quantum dots as a result of the zero-dimensional confinement compared to that of the quantum wells.}
    }

  • R. W. Martin, P. R. Edwards, R. A. Taylor, J. H. Rice, J. H. Na, J. W. Robinson, J. D. Smith, C. Liu, and I. M. Watson, “Luminescence properties of isolated InGaN/GaN quantum dots,” Physica Status Solidi A – Applications and Materials Science, vol. 202, iss. 3, p. 372–376, 2005.
    [BibTeX] [Abstract] [Download PDF]

    InxGa1?xN quantum dots have been fabricated by the selective growth of GaN micro-pyramid arrays topped with InGaN/GaN quantum wells. The spatially- and spectrally-resolved luminescence properties of these structures were measured using low-temperature micro-photoluminescence spectroscopy. The presence of InGaN quantum dots was confirmed directly by the observation of sharp peaks in the emission spectrum at the pyramid apices. These luminescence peaks exhibit linewidths down to 650 {\ensuremath{\mu}}eV (limited by the spectrometer resolution). We describe the broadening of the luminescence peak from a single dot as a function of temperature and excitation power.

    @article{strathprints10018,
    volume = {202},
    number = {3},
    month = {February},
    author = {R.W. Martin and P.R. Edwards and R.A. Taylor and J.H. Rice and J.H. Na and J.W. Robinson and J.D. Smith and C. Liu and I.M. Watson},
    title = {Luminescence properties of isolated InGaN/GaN quantum dots},
    journal = {Physica Status Solidi A - Applications and Materials Science},
    pages = {372--376},
    year = {2005},
    keywords = {physics, Physics, Electronic, Optical and Magnetic Materials, Condensed Matter Physics},
    url = {http://strathprints.strath.ac.uk/10018/},
    abstract = {InxGa1?xN quantum dots have been fabricated by the selective growth of GaN micro-pyramid arrays topped with InGaN/GaN quantum wells. The spatially- and spectrally-resolved luminescence properties of these structures were measured using low-temperature micro-photoluminescence spectroscopy. The presence of InGaN quantum dots was confirmed directly by the observation of sharp peaks in the emission spectrum at the pyramid apices. These luminescence peaks exhibit linewidths down to 650 {\ensuremath{\mu}}eV (limited by the spectrometer resolution). We describe the broadening of the luminescence peak from a single dot as a function of temperature and excitation power.}
    }

  • P. R. Edwards, R. W. Martin, I. M. Watson, C. Liu, R. A. Taylor, J. H. Rice, J. H. Na, J. W. Robinson, and J. D. Smith, “Quantum dot emission from site-controlled InGaN/GaN micropyramid arrays,” Applied Physics Letters, vol. 85, iss. 19, p. 4281–4283, 2004.
    [BibTeX] [Abstract] [Download PDF]

    InxGa1?xN quantum dots have been fabricated by the selective growth of GaN micropyramid arrays topped with InGaN/GaN quantum wells. The spatially, spectrally, and time-resolved emission properties of these structures were measured using cathodoluminescence hyperspectral imaging and low-temperature microphotoluminescence spectroscopy. The presence of InGaN quantum dots was confirmed directly by the observation of sharp peaks in the emission spectrum at the pyramid apices. These luminescence peaks exhibit decay lifetimes of approximately 0.5 ns, with linewidths down to 650 meV

    @article{strathprints3003,
    volume = {85},
    number = {19},
    month = {November},
    author = {P.R. Edwards and R.W. Martin and I.M. Watson and C. Liu and R.A. Taylor and J.H. Rice and J.H. Na and J.W. Robinson and J.D. Smith},
    title = {Quantum dot emission from site-controlled InGaN/GaN micropyramid arrays},
    journal = {Applied Physics Letters},
    pages = {4281--4283},
    year = {2004},
    keywords = {quantum dot emission, InGaN/GaN micropyramid arrays, nanoscience, Solid state physics. Nanoscience, Physics and Astronomy (miscellaneous)},
    url = {http://strathprints.strath.ac.uk/3003/},
    abstract = {InxGa1?xN quantum dots have been fabricated by the selective growth of GaN micropyramid arrays topped with InGaN/GaN quantum wells. The spatially, spectrally, and time-resolved emission properties of these structures were measured using cathodoluminescence hyperspectral imaging and low-temperature microphotoluminescence spectroscopy. The presence of InGaN quantum dots was confirmed directly by the observation of sharp peaks in the emission spectrum at the pyramid apices. These luminescence peaks exhibit decay lifetimes of approximately 0.5 ns, with linewidths down to 650 meV}
    }