InGaN quantum dot green light-emitting diodes with negligible blue shift of electroluminescence peak wavelength

Lv, Wenbin; Wang, Lai; Wang, Lei; Xing, Yuchen; Yang, Di; Hao, Zhibiao; Luo, Yi

doi:10.7567/apex.7.025203

Cited by 30 publications

(19 citation statements)

References 40 publications

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“…In order to circumvent this problem inherent in InGaN QW active layers, an alternative InGaN quantum dot (QD) structure has been suggested as light-emitters in the green or longer spectral ranges. It has been shown both theoretically [ 8 , 9 ] and experimentally [ 10 , 11 ] that the piezoelectric polarization field and resulting quantum-confined Stark effect (QCSE) in InGaN QDs are much smaller than in QWs. Moreover, InGaN QDs inherently contain a lower density of structural defects due to the build-in strain field, leading to a reduced efficiency droop and a higher brightness [ 11 , 12 ].…”

Section: Introductionmentioning

confidence: 99%

Strong localization effect and carrier relaxation dynamics in self-assembled InGaN quantum dots emitting in the green

et al. 2015

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Strong localization effect in self-assembled InGaN quantum dots (QDs) grown by metalorganic chemical vapor deposition has been evidenced by temperature-dependent photoluminescence (PL) at different excitation power. The integrated emission intensity increases gradually in the range from 30 to 160 K and then decreases with a further increase in temperature at high excitation intensity, while this phenomenon disappeared at low excitation intensity. Under high excitation, about 40% emission enhancement at 160 K compared to that at low temperature, as well as a higher internal quantum efficiency (IQE) of 41.1%, was observed. A strong localization model is proposed to describe the possible processes of carrier transport, relaxation, and recombination. Using this model, the evolution of excitation-power-dependent emission intensity, shift of peak energy, and linewidth variation with elevating temperature is well explained. Finally, two-component decays of time-resolved PL (TRPL) with various excitation intensities are observed and analyzed with the biexponential model, which enables us to further understand the carrier relaxation dynamics in the InGaN QDs.

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Section: Introductionmentioning

confidence: 99%

Strong localization effect and carrier relaxation dynamics in self-assembled InGaN quantum dots emitting in the green

et al. 2015

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“…Photoluminescence (PL) technique, a nondestructive and powerful method , has been widely used for the investigation of optical and electrical characters of semiconductors, such as carriers lifetime 1 2 , luminescence of impurities 3 4 and band structures 5 6 7 . Moreover, the PL technique is also an effective method for investigating the novel characters of low-dimensional structure, such as quantum wells 8 9 10 , quantum wires 11 12 13 and quantum dots 14 15 and an useful tool for exploring new materials for optical and electrical devices 16 17 . Because of the importance of the PL technique, it is crucial to get a deeper understanding of the PL process, especially the transport of photogenerated carriers in the PL process.…”

mentioning

confidence: 99%

Investigation of temperature-dependent photoluminescence in multi-quantum wells

Fang

Wang

Sun

et al. 2015

Sci Rep

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Photoluminescence (PL) is a nondestructive and powerful method to investigate carrier recombination and transport characteristics in semiconductor materials. In this study, the temperature dependences of photoluminescence of GaAs-AlxGa1-xAs multi-quantum wells samples with and without p-n junction were measured under both resonant and non-resonant excitation modes. An obvious increase of photoluminescence(PL) intensity as the rising of temperature in low temperature range (T < 50 K), is observed only for GaAs-AlxGa1-xAs quantum wells sample with p-n junction under non-resonant excitation. The origin of the anomalous increase of integrated PL intensity proved to be associated with the enhancement of carrier drifting because of the increase of carrier mobility in the temperature range from 15 K to 100 K. For non-resonant excitation, carriers supplied from the barriers will influence the temperature dependence of integrated PL intensity of quantum wells, which makes the traditional methods to acquire photoluminescence characters from the temperature dependence of integrated PL intensity unavailable. For resonant excitation, carriers are generated only in the wells and the temperature dependence of integrated PL intensity is very suitable to analysis the photoluminescence characters of quantum wells.

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“…Atomic force microscopy investigations on uncapped a -plane InGaN QD structures reveal QD heights of the order of 7±3 nm 45 . For capped polar InGaN/GaN QDs, lens-shaped structures with heights of 3–4 nm and diameters between 25–40 nm have been reported in the literature 59 . This information presents the starting point for our calculations in terms of dot size and shape.…”

Section: Methodsmentioning

confidence: 99%

Deterministic optical polarisation in nitride quantum dots at thermoelectrically cooled temperatures

Wang

Puchtler

Patra

et al. 2017

Sci Rep

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We report the successful realisation of intrinsic optical polarisation control by growth, in solid-state quantum dots in the thermoelectrically cooled temperature regime (≥200 K), using a non-polar InGaN system. With statistically significant experimental data from cryogenic to high temperatures, we show that the average polarisation degree of such a system remains constant at around 0.90, below 100 K, and decreases very slowly at higher temperatures until reaching 0.77 at 200 K, with an unchanged polarisation axis determined by the material crystallography. A combination of Fermi-Dirac statistics and k·p theory with consideration of quantum dot anisotropy allows us to elucidate the origin of the robust, almost temperature-insensitive polarisation properties of this system from a fundamental perspective, producing results in very good agreement with the experimental findings. This work demonstrates that optical polarisation control can be achieved in solid-state quantum dots at thermoelectrically cooled temperatures, thereby opening the possibility of polarisation-based quantum dot applications in on-chip conditions.

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InGaN quantum dot green light-emitting diodes with negligible blue shift of electroluminescence peak wavelength

Cited by 30 publications

References 40 publications

Strong localization effect and carrier relaxation dynamics in self-assembled InGaN quantum dots emitting in the green

Strong localization effect and carrier relaxation dynamics in self-assembled InGaN quantum dots emitting in the green

Investigation of temperature-dependent photoluminescence in multi-quantum wells

Deterministic optical polarisation in nitride quantum dots at thermoelectrically cooled temperatures

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