GaInN quantum well design and measurement conditions affecting the emission energy S‐shape

Netzel, Carsten; Hatami, Soheil; Hoffmann, Veit; Wernicke, Tim; Knauer, A.; Kneissl, Michael; Weyers, M.

doi:10.1002/pssc.201000956

Cited by 7 publications

(11 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The turning points are at higher temperature when the indium mol fraction is increased (first turning point temperatures listed in table 1). These features point strongly to charge carrier localization effects [29][30][31]. The emission energy 'S-shape' behavior is not as pronounced as in most c-plane GaInN quantum well structures (e.g.…”

Section: Evidence For Strong Localizationmentioning

confidence: 93%

Strong charge carrier localization interacting with extensive nonradiative recombination in heteroepitaxially grown m-plane GaInN quantum wells

Netzel¹,

Mauder²,

Wernicke³

et al. 2011

Semicond. Sci. Technol.

View full text Add to dashboard Cite

The development of GaInN quantum well structures with nonpolar crystal orientation for light-emitting diodes and semiconductor lasers is currently one of the main foci of III-nitride-based optoelectronics research. One of the advantages of nonpolar orientations is the absence of polarization fields perpendicular to the quantum well plane. As a consequence, radiative recombination rates are higher compared to quantum wells on polar surfaces. However, due to high densities of threading dislocations and basal plane stacking faults in the case of heteroepitaxially grown nonpolar layers, and due to band gap inhomogeneities in the GaInN quantum wells, characterization of radiative and nonradiative recombination mechanisms is a complex challenge. So far, most published data about band gap fluctuations, charge carrier localization and internal quantum efficiency in nonpolar quantum wells are ambiguous. Here, we present temperature and excitation power density-dependent photoluminescence data featuring multiple characteristics related to strong charge carrier localization in m-plane (1-100) GaInN quantum wells. Thermally activated redistribution of charge carriers between localization sites in these quantum wells is weaker than in polar c-plane ones. The localization strength increases with higher indium concentration in the quantum wells. In the heteroepitaxially grown quantum well structures, the internal quantum efficiency is reduced even at low temperatures (T = 10 K) and especially for m-plane quantum wells with high indium mole fractions.

show abstract

Section: Evidence For Strong Localizationmentioning

confidence: 93%

Strong charge carrier localization interacting with extensive nonradiative recombination in heteroepitaxially grown m-plane GaInN quantum wells

Netzel¹,

Mauder²,

Wernicke³

et al. 2011

Semicond. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Thus, when the localization degree is increased, peak wavelength features a stronger red‐shift and the S‐shaped curve moves to higher temperatures. Gaussian band‐tail model:

E true(T true) = E true(0 true) ‐ α T^{2} / true(β + T true) ‐ σ^{2} / k_{B} T

can be applied to fit the “S”‐shaped curve , where E (0) is the transition energy at 0 K, α, and β are known as Varshni thermal coefficients, and broadening factor σ represents the localization degree. The fitting results and the parameters are shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

The influences of sputtered AlN buffer layer on AlInGaN based blue and near‐ultraviolet light emitting diodes

Wang¹,

Chen²,

Xing

et al. 2017

Physica Status Solidi (a)

View full text Add to dashboard Cite

Instead of conventional GaN buffer layer, a sputtered AlN buffer layer is utilized on the patterned sapphire substrate in AlInGaN based 450-nm blue and 380-nm near-ultraviolet light emitting diodes (LEDs). As a result, the full-width at half maximum (FWHM) of GaN (002) and (102) X-ray diffraction rocking curve decrease from 220 to 135 arcsec and from 245 to 172 arcsec, respectively. Consequently, peak external quantum efficiency (EQE) of 380-nm LED is enhanced by 18-66%, while the EQE of the 450-nm one shows inconspicuous improvement. This phenomenon implies that the radiative recombination efficiency is more sensitive to dislocation density in 380-nm LED. Fitting results of temperaturedependent photoluminescence spectra indicate that the carrier localization effect is weakened as indium composition decreases in the active region, which is regarded as one ordinary explanation. Moreover, carrier lifetimes in 450-and 380-nm LEDs are also measured. The shorter carrier lifetime in 380-nm LED is considered as another key factor.

show abstract

“…The absorbed pump power density was determined from the measured incident power density by utilizing the absorption coefficient extrapolated to 380 nm from the measured optical gain spectra using a model fit. As the excitation takes place close to the quantum well band edge, this procedure takes into account the strong change of absorption due to band filling [9]. Moreover, the waveguide loss was determined from the low energy tail of the gain spectra [10].…”

Section: Measurements and Resultsmentioning

confidence: 99%

Towards green lasing: ingredients for a green laser diode based on GaInN

Dräger

Jönen

Bremers

et al. 2009

Phys. Status Solidi (c)

View full text Add to dashboard Cite

Laser structures based on GaInN quantum wells were investigated using the variable stripe length technique. Two major problems in designing a green emitting laser diode were identified. The first one is the decrease of the optical confinement for increasing wavelength. To avoid this limitation and to simultaneously maintain good optical confinement we grew samples with lattice‐matched AlInN lower cladding layers. The second major issue is to push the emission of the structures to longer wavelength by increasing the indium concentration in the quantum well. We demonstrate optical gain up to a wavelength of 480 nm (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

GaInN quantum well design and measurement conditions affecting the emission energy S‐shape

Cited by 7 publications

References 7 publications

Strong charge carrier localization interacting with extensive nonradiative recombination in heteroepitaxially grown m-plane GaInN quantum wells

Strong charge carrier localization interacting with extensive nonradiative recombination in heteroepitaxially grown m-plane GaInN quantum wells

The influences of sputtered AlN buffer layer on AlInGaN based blue and near‐ultraviolet light emitting diodes

Towards green lasing: ingredients for a green laser diode based on GaInN

Contact Info

Product

Resources

About