Internal quantum efficiency in 6.1 Å superlattices of 77% for mid-wave infrared emitters

Muhowski, Aaron J.; Muellerleile, A. M.; Olesberg, J. T.; Prineas, J. P.

doi:10.1063/5.0013854

Cited by 13 publications

(5 citation statements)

References 26 publications

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“…This PLQY is also close to the room-temperature record of ∼4% observed in epitaxial III–V superlattices. 80 , 81 The ability to engineer QDs with slow nonradiative relaxation is important for mid-infrared photodetectors, where background noise is fundamentally limited by the nonradiative relaxation of thermal carriers. 8 Long lifetimes and high quantum yields should also support mid-infrared emission or lasing by enabling longer gain lifetimes, lower oscillation thresholds, and smaller saturation intensities.…”

Section: Resultsmentioning

confidence: 99%

Toward Bright Mid-Infrared Emitters: Thick-Shell n-Type HgSe/CdS Nanocrystals

2021

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A procedure is developed for the growth of thick, conformal CdS shells that preserve the optical properties of 5 nm HgSe cores. The n-doping of the HgSe/CdS core/shell particles is quantitatively tuned through a simple postsynthetic Cd treatment, while the doping is monitored via the intraband optical absorption at 5 μm wavelength. Photoluminescence lifetime and quantum yield measurements show that the CdS shell greatly increases the intraband emission intensity. This indicates that decoupling the excitation from the environment reduces the nonradiative recombination. We find that weakly n-type HgSe/CdS are the brightest solution-phase mid-infrared chromophores reported to date at room temperature, achieving intraband photoluminescence quantum yields of 2%. Such photoluminescence corresponds to intraband lifetimes in excess of 10 ns, raising important questions about the fundamental limits to achievable slow intraband relaxation in quantum dots.

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Section: Resultsmentioning

confidence: 99%

Toward Bright Mid-Infrared Emitters: Thick-Shell n-Type HgSe/CdS Nanocrystals

2021

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“…And the band gap can be increased from 0.18 eV (InSb) to 0.725 eV (GaSb) [4,5], and the cutoff wavelength can be adjusted from 1.7 μm (GaSb) to 7.3 μm (InSb) [6]. Therefore, GaInSb crystals can be more widely used in epitaxial substrate materials [7], quantum well lasers [8], high electron mobility transistors [9], thermoelectric materials [10,11], as well as infrared (IR) and near-infrared (NIR) devices [12][13][14][15] and other fields.…”

Section: Introductionmentioning

confidence: 99%

Improving the quality and properties of GaInSb crystal with Al doping

Wang,

Liu,

Liu

et al. 2024

Phys. Scr.

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GaInSb crystal is a promising substrate material that can be used to prepare various high-performance devices. Ga0.86In0.14Sb and Al-doped Ga0.86In0.14Sb (Ga0.86In0.14Sb:Al) crystals were grown with the vertical Bridgman method (VB). The doping concentration of aluminum (Al) is 0.005 - 0.015 molar ratio. The effect of Al doping on the structure and properties of Ga0.86In0.14Sb crystal was studied. The results indicated that Al doping significantly reduced the segregation of indium (In) component in the crystal, with the radial segregation reaching a minimum of 0.051 mol%/mm and the axial segregation reaching a minimum of 0.067 mol%/mm. The doping of Al also improved the crystal quality (lattice structure integrity) of Ga0.86In0.14Sb. The passivation and compensation of Al on the intrinsic defects of Ga0.86In0.14 Sb crystal significantly inhibited the generation of dislocation, of which density decreased to 2.461 × 103 cm-2. The doping of Al as the equivalent electron element of gallium (Ga) and In not only made the carrier concentration increase to 1.848 × 1018 cm-3 but also made the carrier mobility increase to 1.982 × 103 cm2/(V·s), resulting in the resistivity decreasing to 1.261 × 10−3 Ω·cm.

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“…Compared to QWs or SLs having type-I (spatially direct) band offsets, they offer a combination of enhanced electrical confinement and intrinsically low Auger recombination rates [36]. This can enhance internal quantum efficiency by respectively mitigating carrier leakage and reducing nonradiative losses [37,38]. InAs/GaSb SLs, already the basis of demonstrated mid-infrared photodetectors [39][40][41], have continued to attract interest as a candidate for the development of mid-infrared LEDs.…”

Section: Introductionmentioning

confidence: 99%

Theory and optimisation of radiative recombination in broken-gap InAs/GaSb superlattices

Murphy,

O’Reilly,

Broderick

2023

J. Phys. D: Appl. Phys.

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We present a theoretical analysis of mid-infrared radiative recombination in InAs/GaSb superlattices (SLs). We employ a semi-analytical plane wave expansion method in conjunction with an 8-band k·p Hamiltonian to compute the SL electronic structure, paying careful attention to the identification and mitigation of spurious solutions. The calculated SL eigenstates are used directly to compute spontaneous emission spectra and the radiative recombination coefficient B. We elucidate the origin of the relatively large B coefficients in InAs/GaSb SLs which, despite the presence of spatiallyindirect (type-II-like) carrier confinement, are close to that of bulk InAs and compare favourably to those calculated for mid-infrared type-I pseudomorphic and metamorphic quantum well structures having comparable emission wavelengths. Our analysis explicitly quantifies the roles played by carrier localisation (specifically, partial delocalisation of bound electron states) and miniband formation (specifically, miniband occupation and optical selection rules) in determining the magnitude of B and its temperature dependence. We perform a high-throughput optimisation of the room temperature B coefficient in InAs/GaSb SLs across the 3.5 – 7 μm wavelength range, quantifying the dependence of B on the relative thickness of the electron-confining InAs and hole-confining GaSb layers. This analysis provides guidance for the growth of optimised SLs for mid-infrared light emitters. Our results, combined with the expected low non-radiative Auger recombination rates in structures having spatially indirect electron and hole confinement, corroborate recently observed high output power in prototype InAs/GaSb SL inter-band cascade light-emitting diodes.

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Internal quantum efficiency in 6.1 Å superlattices of 77% for mid-wave infrared emitters

Cited by 13 publications

References 26 publications

Toward Bright Mid-Infrared Emitters: Thick-Shell n-Type HgSe/CdS Nanocrystals

Toward Bright Mid-Infrared Emitters: Thick-Shell n-Type HgSe/CdS Nanocrystals

Improving the quality and properties of GaInSb crystal with Al doping

Theory and optimisation of radiative recombination in broken-gap InAs/GaSb superlattices

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