Ultraviolet light emitting diodes using III-N quantum dots

Brault, J.; Matta, Samuel; Ngo, Thi-Huong; Rosales, Daniel; Leroux, M.; Damilano, B.; Khalfioui, M. Al; Tendille, Florian; Chenot, Sébastien; Mierry, P. de; Massies, J.; Gil, Bernard

doi:10.1016/j.mssp.2016.02.014

Cited by 16 publications

(15 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These very high QD densities are attributed to the low growth temperature of 720°C used during the AlyGa1-yN deposition and consequently the low diffusion length of Ga and Al adatoms. 23,24 Concerning the QD size distribution, their lateral dimensions are typically ranging between 5 and 15 nm and their heights between 1.5 and 2.5 nm. PL measurements, using a frequency-doubled Ar laser excitation source at 244 nm, of reference AlyGa1-yN QD samples are shown in Figure 2 and compared with GaN QD.…”

Section: Resultsmentioning

confidence: 99%

DUV LEDs based on AlGaN quantum dots

Brault¹,

Khalfioui²,

Leroux³

et al. 2021

Gallium Nitride Materials and Devices XVI

Self Cite

View full text Add to dashboard Cite

Deep ultra-violet (DUV) light emitting diodes (LED) are expected to be the next generation of UV sources, offering significant advantages such as compactness, low consumption and long lifetimes. Yet, improvements of their performances are still required and the potential of AlyGa1-yN quantum dots as DUV emitters is investigated in this study. Using a stress induced growth mode transition, quantum dots (QD) are spontaneously formed on Al0.7Ga0.3N/AlN heterostructures grown on sapphire substrates by molecular beam epitaxy. By increasing the QD Al composition, a large shift of the QD photoluminescence in the UV range is observed, going from an emission in the near UV for GaN QD down to the UVC region for Al0.4Ga0.6N QD. A similar behavior is observed for electroluminescence (EL) measurements performed on LED structures and an emission ranging from the UVA (320-340 nm) down to the UVC (265-280 nm) has been obtained. The main performances of Al0.7Ga0.3N based QD LED are presented in terms of electrical and optical characteristics. In particular, the emission dependence on the input current density, including the emitted wavelength, the optical power and the external quantum efficiency are shown and discussed.

show abstract

Section: Resultsmentioning

confidence: 99%

DUV LEDs based on AlGaN quantum dots

Brault¹,

Khalfioui²,

Leroux³

et al. 2021

Gallium Nitride Materials and Devices XVI

Self Cite

View full text Add to dashboard Cite

show abstract

“…Binary and ternary III–V have attracted increasing interest with the display of quantum confinement effect and size‐related properties with decreasing particle diameter [11,12] . III–V quantum dots (QDs) are excellent candidates for solid state lighting devices [13] with a precise control of emission wavelengths from ultraviolet ((Al,Ga)N [14] ) to infrared (InAs) [15] . The current outlook for these systems includes their use in photonic waveguides, [16,17] their implementation in trace‐gas or chemical sensing devices [18–20] and their use as replacement for organic phosphors in OLED‐like structures [21–23] .…”

Section: Figurementioning

confidence: 99%

Chemistry Platform for the Ultrafast Continuous Synthesis of High‐Quality III–V Quantum Dots

Giroire

Garcia

Marre

et al. 2021

Chemistry A European J

View full text Add to dashboard Cite

A chemistry platform for the fast continuous synthesis of III-V quantum dots is demonstrated. III-nitride QDs are prepared by using short residence times (less than 30 s) in a one-step continuous process with supercritical solvents. GaN QDs prepared via this route exhibit strong UV photoluminescence with a structuring of the emission signal at low temperature (5 K), confirming their high quality. An example of metal site substitution is given with the synthesis of In x Ga 1-x N solid solution. A continuous bandgap shift towards lower energies is demonstrated when increasing the indium content with strong photoluminescence signals from UV to visible. The chemistry platform proposed could be easily extrapolated to binary and ternary III phosphides or arsenides with the homologous V source. III-V semiconductors have been well studied for the past 40 years due to their excellent optoelectronic properties. [1][2][3][4] A wide range of applications can be achieved with bulk III-V semiconductors such as laser diodes (GaN, [5] GaInAsN/GaAs [6,7] ) and UV detection (GaN, [8] GaInP-AlInP-GaAs, [9] AlGaN [10] ). Binary and ternary III-V have attracted increasing interest with the display of quantum confinement effect and size-related properties with decreasing particle diameter. [11,12] III-V quantum dots (QDs) are excellent candidates for solid state lighting devices [13] with a precise control of emission wavelengths from ultraviolet ((Al,Ga)N [14] ) to infrared (InAs). [15] The current outlook for these systems includes their use in photonic waveguides, [16,17] their implementation in trace-gas or chemical sensing devices [18][19][20] and their use as replacement for organic phosphors in OLEDlike structures. [21][22][23] III-V QDs are also among the best lead-free and cadmium-free candidates for bio-related applications [24] such as bio-imaging, [25] bio-sensing [26] and bio-integrated devices. [27] However, the preparation of high quality III-V QDs with size and morphology control can be challenging compared to II-VI semiconductors, [26] especially CdSe, where size control [28,29] and shape control have been widely demonstrated. [30,31] Synthesis in supercritical fluids has been established as an efficient method

show abstract

“…In particular, by using semipolar orientations, the internal electric field can be drastically reduced as compared to the polar (0001) surface, which enables the emission shift to shorter wavelengths [14]. Using this approach we were able to fabricate (1122) QD-based UV LEDs emitting at much shorter wavelengths than their (0001) oriented counterparts [15].…”

Section: Introductionmentioning

confidence: 99%

GaN quantum dot polarity determination by X-ray photoelectron diffraction

Romanyuk

Bartoš

Brault

et al. 2016

Applied Surface Science

View full text Add to dashboard Cite

Growth of GaN quantum dots (QDs) on polar and semipolar GaN substrates is a promising technology for efficient nitride-based light emitting diodes (LED) due to suppressed dislocation density in the active region of the devices. The QDs crystal orientation typically repeats the polarity of the substrate. In case of non-polar or semipolar substrates, the polarity of QDs is not obvious. In this article, the polarity of GaN QDs and of underlying layers was investigated nondestructively by X-ray photoelectron diffraction (XPD). Polar and semipolar GaN/Al 0.5 Ga 0.5 N heterostructures were grown on the sapphire substrates with (0001) and (1100) orientations by molecular beam epitaxy (MBE). Polar angle dependence of N 1s core-level photoelectron intensities were measured from GaN QDs and compared with the corresponding experimental curves from freestanding GaN crystals. It is confirmed experimentally, that the crystalline orientation of polar (0001) GaN QDs follows the orientation of the (0001) sapphire substrate. In case of semipolar GaN QDs grown on (1100) sapphire substrate, the (1122) polarity of QDs was determined.

show abstract

Ultraviolet light emitting diodes using III-N quantum dots

Cited by 16 publications

References 40 publications

DUV LEDs based on AlGaN quantum dots

DUV LEDs based on AlGaN quantum dots

Chemistry Platform for the Ultrafast Continuous Synthesis of High‐Quality III–V Quantum Dots

GaN quantum dot polarity determination by X-ray photoelectron diffraction

Contact Info

Product

Resources

About