Progress in the optical studies of single InGaN/GaN quantum dots

Non‐linear excitation and correlation studies of single InGaN quantum dots

“…A consequence of this is a more sporadic spread of spatial QD positions, with dots present both in the In rich InGaN layers and directly on top of the GaN. It is this wetting layer that produces the spectrally broad emission seen in previous studies [9]. Following sample growth, a 100 nm thick Al layer was evaporated onto the sample surface and a mask pattern fabricated using electron-beam lithography.…”

“…It exists as a doubly interesting phenomenon due both to its fundamental nature and its use in such areas as microscopy [6] and biological fluorescence spectroscopy [7]. It has recently become clear [8,9] that such excitation techniques can be used as a background suppressant in InGaN QD samples. In such cases the wetting layer (WL) emission is normally dominant under single photon excitation thus drowning out much of the QD signal.…”

Observations of Rabi oscillations in a non-polar InGaN quantum dot

“…In this letter, we use non-polar a-plane (1120) InGaN quantum dots to show experimental evidence of power-dependent Rabi oscillations between an excitonic excited state |1 and the crystal ground state |0 . After resonant excitation into the exciton excited state |1 , the exciton relaxes into the excitonic ground state |s , and the photoluminescence (PL) from this state is used as an indirect measurement of the population of the excited state, enabling observation of Rabi oscillations in the blue spectral region which houses the fastest commercially available single photon detectors [15].…”

Electroluminescence from isolated single indium gallium nitride quantum dots up to 150 K

“…By incorporating quantum dots (QDs) rather than quantum wells as active region, further improvements could be demonstrated, such as better electron confinement and thus a higher temperature stability of the luminescence than for quantum well based structures 1, 2. Over the past years, InGaN QD ensembles as well as single InGaN QDs have been investigated under optical excitation concerning many properties like excitonic binding energies, radiative lifetimes, and excitation dependence of the luminescence 3, temperature stability 4, electron confinement, activation energies 5, etc. Further, first experiments on InGaN QDs incorporated into optical microresonators 6, 7 and QD laser structures 8–10 were reported.…”