Optical studies of degradation of AlGaN quantum well based deep ultraviolet light emitting diodes

Pinos, Andrea; Marcinkevičius, Saulius; Yang, Jinwei; Gaška, R.; Shatalov, M.; Shur, M. S.

doi:10.1063/1.3506697

Cited by 31 publications

(16 citation statements)

References 21 publications

(25 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some of them extend for a few lm, thus, they might contain dislocation clusters rather than individual defects. 16 However, such lower intensity spots do not appear in all scans. Thus, dislocations alone cannot account for areas with an increased rate of the nonradiative recombination.…”

Section: Resultsmentioning

confidence: 96%

High spatial uniformity of photoluminescence spectra in semipolar (202¯1) plane InGaN/GaN quantum wells

Gelžinytė

Ivanov

Marcinkevičius

et al. 2015

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

Articles you may be interested inTemporally and spatially resolved photoluminescence investigation of ( 11 2 ¯ 2 ) semi-polar InGaN/GaN multiple quantum wells grown on nanorod templates Appl. Phys. Lett. 105, 261103 (2014); 10.1063/1.4905191Highly polarized photoluminescence and its dynamics in semipolar ( 20 2 ¯ 1 ¯ ) InGaN/GaN quantum well Appl. Phys. Lett.High optical polarization ratio of semipolar ( 20 2 ¯ 1 ¯ ) -oriented InGaN/GaN quantum wells and comparison with experiment J. Appl. Phys. 112, 093106 (2012); 10.1063/1.4764316 Dynamics of polarized photoluminescence in m -plane InGaN/GaN quantum wellsScanning near-field optical spectroscopy was applied to study spatial variations of emission spectra at room temperature in semipolar ð20 21Þ In x Ga 1Àx N/GaN single quantum wells (QWs) for 0:11 x 0:36. Photoluminescence (PL) was found to be highly uniform, with peak wavelength deviations and peak intensity deviations divided by average values in the range of 6-12 meV and 0.03-0.07, respectively. Near-field maps of PL parameters showed large, $5 to 10 lm size areas of similar values, as opposed to 100 nm scale variations, often reported for InGaN QWs. The nearfield PL spectra were found to broaden with increasing InN molar fraction. In the low In content QWs, the broadening is primarily determined by the random cation distribution, while for larger InN molar fractions 10 nm scale localization sites with increasingly deeper band potentials are suggested as the linewidth broadening cause. V C 2015 AIP Publishing LLC.

show abstract

Section: Resultsmentioning

confidence: 96%

High spatial uniformity of photoluminescence spectra in semipolar (202¯1) plane InGaN/GaN quantum wells

Gelžinytė

Ivanov

Marcinkevičius

et al. 2015

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Nitrogen vacancies V N , [11,14,[17][18][19]] sites of out-diffused Al, [11][12][13] and oxides of Al or Ga [11,20- The study of the photomodification is of special interest in view of the development of AlGaN-based UV LDs and high-power FETs, since high injected carrier densities are typical for these devices.…”

Section: Discussionmentioning

confidence: 99%

Photomodification of carrier lifetime and diffusivity in AlGaN epitaxial layers

Podlipskas

Aleksiejūnas

Наргелас

et al. 2016

Current Applied Physics

View full text Add to dashboard Cite

Nonradiative recombination rate and diffusivity of nonequilibrium carriers were modified by intense laser pulses in AlGaN epilayers with Al content ranging from 16 to 71%. The epilayers were examined before and after the photomodification using light-induced transient grating and photoluminescence spectroscopy techniques. The photomodification resulted in (i) enhancement of the nonradiative recombination rate and (ii) large changes of the diffusion coefficient of the nonequilibrium carriers, without imposing any macroscopic structural damage to the epilayers. The photomodification effect on the recombination rate was stronger in the layers with higher Al content indicating the involvement of the Al atoms in this process. The carrier diffusivity exhibited a rapid initial increase as a consequence of the photomodification followed by a slow decline, as the photomodification duration was increased. The enhancement of the diffusion coefficient of up to 2.4 times was accompanied by 13% decrease in the carrier lifetime.

show abstract

“…One possibility is that an increase in leakage current could signify an increase in non-radiative states that are created when electrons aggressively make it through the quantum wells and electron block into the p-type cladding layer. 10 What is unknown is in the voltage range of the secondary slope (3-4 V) why the increase in current at time zero is so much more than after aged conditions. This type of degradation monitoring by laser spotting is still in a preliminary stage and must be further developed.…”

Section: Stress Conditions and Changes Over Timementioning

confidence: 99%

“…Recent studies of UV LED degradation have identified a discrepancy between PL and EL measurements. 5,9,10 The degradation in PL (which targets the quantum wells) is either negligible or significantly less than the orders of magnitude decrease in photon counts encountered in the EL measurements. This suggests that the degradation is not occurring in the active region but more likely in the p-type cladding material increasing the number of nitrogen vacancies.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of failure modes in deep UV and deep green LEDs utilizing advanced semiconductor localization techniques.

Tangyunyong¹,

Miller²,

Cole³

2012

View full text Add to dashboard Cite

We present the results of a two-year early career LDRD that focused on defect localization in deep green and deep ultraviolet (UV) light-emitting diodes (LEDs). We describe the laser-based techniques (TIVA/LIVA) used to localize the defects and interpret data acquired. We also describe a defect screening method based on a quick electrical measurement to determine whether defects should be present in the LEDs. We then describe the stress conditions that caused the devices to fail and how the TIVA/LIVA techniques were used to monitor the defect signals as the devices degraded and failed. We also describe the correlation between the initial defects and final degraded or failed state of the devices. Finally we show characterization results of the devices in the failed conditions and present preliminary theories as to why the devices failed for both the InGaN (green) and AlGaN (UV) LEDs. 4 ACKNOWLEDGMENTSThe authors are thankful for the assistance of Darlene Udoni for her technical support throughout this project, as well as Michael Rye and Paul Kotula for their expertise and materials characterization support. We also appreciate the backing of managers David Stein and Andy Boye throughout this work.5

show abstract

Optical studies of degradation of AlGaN quantum well based deep ultraviolet light emitting diodes

Abstract: Articles you may be interested inHigh current-induced degradation of AlGaN ultraviolet light emitting diodes

Cited by 31 publications

References 21 publications

High spatial uniformity of photoluminescence spectra in semipolar (202¯1) plane InGaN/GaN quantum wells

High spatial uniformity of photoluminescence spectra in semipolar (202¯1) plane InGaN/GaN quantum wells

Photomodification of carrier lifetime and diffusivity in AlGaN epitaxial layers

Characterization of failure modes in deep UV and deep green LEDs utilizing advanced semiconductor localization techniques.

Contact Info

Product

Resources

About