Quantum dot emission from site-controlled InGaN∕GaN micropyramid arrays

Edwards, P. R.; Martin, Robert; Watson, I. M.; Liu, C.; Taylor, Robert A.; Rice, James H.; Na, J.H.; Robinson, James W.; Smith, J. D.

doi:10.1063/1.1815043

Cited by 52 publications

(36 citation statements)

References 13 publications

(12 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, it is nearly impossible to directly measure all the relevant structural parameters of every single QD non-destructively with sufficient accuracy using current technologies [4]. Furthermore, the correlation between the optical properties and the structural parameters was obscure in previous studies in which the QDs were typically formed at random positions with large structural inhomogeneity [5,6].…”

Section: Introductionmentioning

confidence: 99%

Carrier dynamics in site- and structure-controlled InGaN/GaN quantum dots

et al. 2014

View full text Add to dashboard Cite

We report on the carrier dynamics in InGaN/GaN dot-in-nanowire quantum dots revealed by systematic mapping between optical properties and structural parameters of the quantum dots. Such a study is made possible by using quantum dots with precisely controlled locations and sizes. We show that the carrier dynamics is governed by two competing mechanisms: 1) excitons are protected from surface recombination by a potential barrier formed due to strain-relaxation at the sidewall surface; 2) excitons can overcome the potential barrier by tunnelling and thermal activation. This carrier dynamics model successfully explains the following surprising experimental findings on individual quantum dots. Firstly, there exist strong statistical correlations among multiple optical properties of many individual quantum dots, despite variations of these properties resulting from inevitable structural variations among the quantum dots. Secondly, the antibunching property of quantum dot emission exhibits abnormal ladle-shaped dependence on the decay time and temperature. Our results can guide the way toward nitride-based high temperature singlephoton emitters and nano-photonic devices.

show abstract

Section: Introductionmentioning

confidence: 99%

Carrier dynamics in site- and structure-controlled InGaN/GaN quantum dots

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Preferential nucleation sites with finite areas created by in situ electron beam lithography 6 and prefabricated pyramidal [7][8][9][10][11] or nanowire [12][13][14] templates have been demonstrated to obtain site-controlled QDs. However, these approaches do not provide any obvious path to polarization control.…”

Section: Introductionmentioning

confidence: 99%

Direct generation of linearly polarized photon emission with designated orientations from site-controlled InGaN quantum dots

et al. 2014

View full text Add to dashboard Cite

Semiconductor quantum dots (QDs) have been demonstrated viable for efficient light emission applications, in particular for the emission of single photons on demand. However, the preparation of QDs emitting photons with predefined and deterministic polarization vectors has proven arduous. Access to linearly polarized photons is essential for various applications. In this report, a novel concept to directly generate linearly-polarized photons is presented. This concept is based on InGaN QDs grown on top of elongated GaN hexagonal pyramids, by which the predefined elongation determines the polarization vectors of the emitted photons from the QDs. This growth scheme should allow fabrication of ultracompact arrays of photon emitters, with a controlled polarization direction for each individual emitter. Keywords: GaN; InGaN; photoluminescence; polarized emission; quantum dot INTRODUCTION Quantum dots (QDs) have validated their important role in current optoelectronic devices and they are also seen promising as light sources for quantum information applications. An improved efficiency of laser diodes and light-emitting diodes can be achieved by the incorporation of QDs ensembles in the optically active layers.1 In addition, the proposed quantum computer applications rely on photons with distinct energy and polarization vectors, which can be seen as the ultimate demand on photons emitted from individual QDs.2 A common requirement raised for several optoelectronic applications, e.g., liquid-crystal displays, three-dimensional visualization, (bio)-dermatology 3 and the optical quantum computers, 4 is the need of linearly polarized light for their operation. For existing applications, the generation of linearly polarized light is obtained by passing unpolarized light through a combination of polarization selective filters and waveguides, with an inevitable efficiency loss as the result. These losses can be drastically reduced by employment of sources, which directly generate photons with desired polarization directions.Conventional QDs grown via the Stranski-Krastanov (SK) growth mode are typically randomly distributed over planar substrates and possess different degrees of anisotropies. The anisotropy in strain field and/or geometrical shape of each individual QD determines the polarization performance of the QD emission. Accordingly, a cumbersome post-selection of QDs with desired polarization properties among the randomly distributed QDs is required for device integration.

show abstract

“…[11] To control the position of a III-N QD, various approaches have been explored. [12][13][14][15][16][17][18] To date, QD-like emission has only been reported from dots formed at the apex of a sitecontrolled GaN pyramid [12,17] and dots at the top of a site-controlled AlGaN nanowire. [18] But no single photon emission has been reported from these systems yet.…”

mentioning

confidence: 99%

Single photon emission from site-controlled InGaN/GaN quantum dots

Zhang

Teng

Hill

et al. 2013

Applied Physics Letters

View full text Add to dashboard Cite

Single photon emission was observed from site-controlled InGaN/GaN quantum dots. The singlephoton nature of the emission was verified by the second-order correlation function up to 90 K, the highest temperature to date for site-controlled quantum dots. Micro-photoluminescence study on individual quantum dots showed linearly polarized single exciton emission with a lifetime of a few nanoseconds. The dimensions of these quantum dots were well controlled to the precision of state-of-the-art fabrication technologies, as reflected in the uniformity of their optical properties. The yield of optically active quantum dots was greater than 90%, among which 13%-25% exhibited single photon emission at 10 K.Semiconductor quantum dots (QDs) have diverse quantum photonic applications [1,2] [2] However, most work to date has been based on self-assembled QDs in III-As and III-P materials, which face severe limitations in operating temperature and scalability. III-As and III-P QDs typically operate at cryogenic temperatures due to the relatively small exciton binding energies and QD-barrier band offsets. Furthermore, self-assembled QDs are formed at random locations and suffer from large inhomogeneity in size and spectral distribution, which prevents controlled coupling of multiple QDs or coupling of QDs with cavities. In this letter, we report single photon emission from sitecontrolled single InGaN/GaN QDs that are scalable for manufacturing and can be readily integrated with cavities.To achieve cryo-free operation, III-N QDs with large QD-barrier band offsets and exciton binding energies have emerged as one of the most promising solutions. Single photon emission has been reported up to 200 K, although only in a self-assembled GaN/AlN QD[10] and an InGaN QD in a self-organized AlGaN nanowire. [11] To control the position of a III-N QD, various approaches have been explored. [12][13][14][15][16][17][18] To date, QD-like emission has only been reported from dots formed at the apex of a sitecontrolled GaN pyramid [12,17] and dots at the top of a site-controlled AlGaN nanowire.[18] But no single photon emission has been reported from these systems yet.In this work, we fabricated site-controlled InGaN/GaN QDs by dry etching of a planar single quantum well * dengh@umich.edu † peicheng@umich.edu (QW). This structure has been applied to III-As systems but with very limited success, due to the detrimental surface effects introduced by the etched sidewall. [19] In contrast, the surface recombination velocity of III-N is 2-3 orders of magnitude slower than that of IIIAs. [20,21] Bright luminescence has been observed from ensembles of III-N nano-pillars etched from multiple QW structures, [13][14][15] and from a single quantum disk at the room temperature.[22] Yet no clear evidence of single photon emission from these structures have been reported so far. Here we not only show single photon emission from our lithographically defined, scalable single InGaN/GaN QDs but also show that this quantum phenomenon survives at temperatures up to 90...

show abstract

Quantum dot emission from site-controlled InGaN∕GaN micropyramid arrays

Cited by 52 publications

References 13 publications

Carrier dynamics in site- and structure-controlled InGaN/GaN quantum dots

Carrier dynamics in site- and structure-controlled InGaN/GaN quantum dots

Direct generation of linearly polarized photon emission with designated orientations from site-controlled InGaN quantum dots

Single photon emission from site-controlled InGaN/GaN quantum dots

Contact Info

Product

Resources

About