A versatile phenomenological model for the S-shaped temperature dependence of photoluminescence energy for an accurate determination of the exciton localization energy in bulk and quantum well structures

Dixit, V. K.; Porwal, S.; Singh, S. D.; Sharma, T. K.; Ghosh, Sandip; Oak, S. M.

doi:10.1088/0022-3727/47/6/065103

Cited by 42 publications

(23 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reduction in the peak intensity is attributed to the increase in nonradiative recombination of carriers due to thermal quenching. 24 As shown in Fig. 4(c), E a energy also increases as the AlN composition increases in the MQW (E a % 16 meV, 16 meV, 18 meV, and 25 meV, for samples D, C, B, and A, respectively).…”

mentioning

confidence: 73%

Excitonic localization in AlN-rich AlxGa1−xN/AlyGa1−yN multi-quantum-well grain boundaries

Ajia¹,

Edwards²,

Liu³

et al. 2014

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

mentioning

confidence: 73%

Excitonic localization in AlN-rich AlxGa1−xN/AlyGa1−yN multi-quantum-well grain boundaries

Ajia¹,

Edwards²,

Liu³

et al. 2014

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…Beyond this temperature, free carrier recombination dominates, and the regular temperature-induced band gap shrinkage occurs due to the electron-phonon interaction and lattice relaxation. Although the overall temperature behavior of the PL in thin films and nanowires is the same, in the nanowires, an additional red-blue shift is observed around 50 K. Such an additional feature is normally reported to be due to splitting of the heavy hole (HH) and light hole (LH) leading to the corresponding excitonic transitions [ 24 ]. However, the PL spectra shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Effects of Annealing on GaAs/GaAsSbN/GaAs Core-Multi-shell Nanowires

et al. 2016

View full text Add to dashboard Cite

The effects of ex-situ annealing in a N2 ambient on the properties of GaAs/GaAsSbN/GaAs core-multi-shell nanowires on Si (111) substrate grown by self-catalyzed molecular beam epitaxy (MBE) are reported. As-grown nanowires exhibit band edge emission at ~0.99 eV with a shoulder peak at ~0.85 eV, identified to arise from band tail states. A large red shift of 7 cm−1 and broadened Raman spectra of as-grown nanowires compared to that of non-nitride nanowires confirmed phonon localization at N-induced localized defects. On annealing nanowires to 750 °C, there was no change in the planar defects in the nanowire with respect to the as-grown nanowire; however, vanishing of the photoluminescence (PL) peak corresponding to band tail states along with enhanced band edge PL intensity, recovery of the Raman shift and increase in the Schottky barrier height from 0.1 to 0.4 eV clearly point to the efficient annihilation of point defects in these GaAsSbN nanowires. A significant reduction in the temperature-induced energy shift in the annealed nanowires is attributed to annihilation of band tail states and weak temperature dependence of N-related localized states. The observation of room temperature PL signal in the 1.3 μm region shows that the strategy of adding small amounts of N to GaAsSb is a promising route to realization of efficient nanoscale light emitters with reduced temperature sensitivity in the telecommunication wavelength region.

show abstract

“…At lower powers an S-shaped dependence develops (Fig. 8), commonly attributed to potential fluctuations in the InGaAs QW layer [26][27][28]. Though there is little difference between the QW and SML temperature dependencies [29], it can be seen that the S-shaped curve is slightly more pronounced for the QW.…”

Section: Comparison With Quantum Well Samplementioning

confidence: 99%

Heterodimensional charge-carrier confinement in stacked submonolayer InAs in GaAs

et al. 2016

View full text Add to dashboard Cite

Charge-carrier confinement in nanoscale In-rich agglomerations within a lateral InGaAs quantum well (QW) formed from stacked submonolayers (SMLs) of InAs in GaAs is studied. Low-temperature photoluminescence (PL) and magneto-PL clearly demonstrate strong vertical and weak lateral confinement, yielding two-dimensional (2D) excitons. In contrast, high-temperature (400 K) magneto-PL reveals excited states that fit a Fock-Darwin spectrum, characteristic of a zero-dimensional (0D) system in a magnetic field. This paradox is resolved by concluding that the system is heterodimensional: the light electrons extend over several In-rich agglomerations and see only the lateral InGaAs QW, i.e., are 2D, while the heavier holes are confined within the In-rich agglomerations, i.e., are 0D. This description is supported by single-particle effective-mass and eight-band k · p calculations. We suggest that the heterodimensional nature of nanoscale SML inclusions is fundamental to the ability of respective optoelectronic devices to operate efficiently and at high speed.

show abstract

A versatile phenomenological model for the S-shaped temperature dependence of photoluminescence energy for an accurate determination of the exciton localization energy in bulk and quantum well structures

Cited by 42 publications

References 52 publications

Excitonic localization in AlN-rich AlxGa1−xN/AlyGa1−yN multi-quantum-well grain boundaries

Excitonic localization in AlN-rich AlxGa1−xN/AlyGa1−yN multi-quantum-well grain boundaries

Effects of Annealing on GaAs/GaAsSbN/GaAs Core-Multi-shell Nanowires

Heterodimensional charge-carrier confinement in stacked submonolayer InAs in GaAs

Contact Info

Product

Resources

About