The effect of dislocations on the optical absorption of heteroepitaxial InP and GaAs on Si

Iber, H.; Peiner, Erwin; Schlachetzki, A.

doi:10.1063/1.362577

Cited by 17 publications

(14 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This demonstrates that the increase in threshold current density with time occurring during initial rapid degradation is due to an increase in the internal optical mode loss. It is known that internal optical mode loss can increase in the presence of threading dislocations due to the effect of the localised electric field generated by dangling bonds on the local confined state energies [21]. We believe that in the initial stages of degradation there is a relatively large initial increase in the internal optical loss due to dislocation climb.…”

Section: Reliability Testing: Results and Discussionmentioning

confidence: 81%

Degradation of III–V Quantum Dot Lasers Grown Directly on Silicon Substrates

Shutts

Allford

Spinnler

et al. 2019

IEEE J. Select. Topics Quantum Electron.

View full text Add to dashboard Cite

Initial age-related degradation mechanisms for InAs quantum dot lasers grown on silicon substrates emitting at 1.3 µm are investigated. The rate of degradation is observed to increase for devices operated at higher carrier densities and is therefore dependent on gain requirement or cavity length. While carrier localization in quantum dots minimizes degradation, an increase in the number of defects in the early stages of aging can increase the internal optical-loss that can initiate rapid degradation of laser performance due to the rise in threshold carrier density. Population of the two-dimensional states is considered the major factor for determining the rate of degradation, which can be significant for lasers requiring high threshold carrier densities. This is demonstrated by operating lasers of different cavity lengths with a constant current and measuring the change in threshold current at regular intervals. A segmented-contact device, which can be used to measure the modal absorption and also operate as a laser, is used to determine how the internal optical-loss changes in the early stages of degradation. Structures grown on silicon show an increase in internal optical loss, whereas the same structure grown on GaAs shows no signs of increase in internal optical loss when operated under the same conditions.

show abstract

Section: Reliability Testing: Results and Discussionmentioning

confidence: 81%

Degradation of III–V Quantum Dot Lasers Grown Directly on Silicon Substrates

Shutts

Allford

Spinnler

et al. 2019

IEEE J. Select. Topics Quantum Electron.

View full text Add to dashboard Cite

show abstract

“…The thick, highly-doped graded buffer is a potential source of parasitic sub-bandgap absorption by freecarriers 7,8 and/or dislocations. 9,10 These potential sources of absorption are of major concern for TPV applications, because reflection of sub-bandgap light back to the radiator is critical for TPV system conversion efficiency, and is also important for thermal management. The former point is highlighted in panel (i) in Fig.…”

Section: Introductionmentioning

confidence: 99%

Inverted metamorphic AlGaInAs/GaInAs tandem thermophotovoltaic cell designed for thermal energy grid storage application

Schulte

France

Friedman

et al. 2020

Journal of Applied Physics

View full text Add to dashboard Cite

We demonstrate an inverted metamorphic multijunction (IMM) photovoltaic cell comprising lattice-mismatched 1.2 eV AlGaInAs and 1.0 eV GaInAs junctions optimized for high-temperature thermophotovoltaic (TPV) applications. This device differs from traditional IMM solar cells because the mismatched junctions are grown at a single lattice constant. This architecture enables removal of the compositionally graded buffer which otherwise filters light from the junctions below and absorbs subbandgap light via free-carrier absorption. Sub-bandgap absorption dramatically reduces the efficiency of TPV systems using high reflectivity cells to enable bandedge spectrum filtering. Three components required development to enable this device: 1) a latticemismatched 1.2 eV AlGaInAs junction, 2) a metamorphic contact layer grown after the graded buffer, and 3) a transparent tunnel junction that sits in front of the 1.0 eV GaInAs junction. Growth conditions that minimize oxygen defect incorporation maximize AlGaInAs cell quality, enabling a 0.41 V bandgap open circuit voltage offset at 22 mA/cm 2 under AM1.5D. A mismatched GaInAs:Se layer is developed as a low resistance contact. Lastly we develop a GaAsSb:C/GaInP:Se tunnel junction suitable for high-power densities with more transparency than the GaAsSb:C/GaInP:Se structure used in past IMM cells. We characterize the tandem device under a high-intensity spectrum that approximates the emission from a 2150 °C blackbody radiator and deduce a projected ideal TPV efficiency of 39.9% at ~30% of the blackbody irradiance, and 36% ideal TPV efficiency under the full 118 W/cm 2 irradiance. Improvements to the back-surface reflectivity and series resistance are expected to increase the ideal TPV efficiency well above 40%.

show abstract

“…By SE, changes in amplitude and phase of elliptically polarized radiation upon reflection at the epilayer were measured. The absorption coefficient ᾱ and the index of refraction were determined on the basis of a parametrized three-layer model comprising the silicon substrate,the epitaxial layer and a native oxide layer on top [11]. Electron concentration and mobility were determined by the stripping van der Pauw technique [12].…”

Section: Methodsmentioning

confidence: 99%

The effect of threading dislocations on optical absorption and electron scattering in strongly mismatched heteroepitaxial III V compound semiconductors on silicon

Peiner

Guttzeit

Wehmann

2002

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

The effect of threading dislocations on the optical and electrical properties of InP and GaAs heteroepitaxial layers on (001) silicon was investigated. Charged deep states act as scattering centres for electrons, thus affecting the electron mobility at low temperatures. The electric field arising from charged dislocations causes enhanced optical absorption at wavelengths near the fundamental absorption edge. The mean charge of the threading dislocations in GaAs/Si was found to be considerably higher than that for InP/Si. A model is described relating this effect to a regular arrangement of α-type 60 • dislocations at extended twin defects which were observed in InP/Si but were absent in GaAs/Si.

show abstract

The effect of dislocations on the optical absorption of heteroepitaxial InP and GaAs on Si

Abstract: Structural and optical properties of strainrelaxed InAsP/InP heterostructures grown by metalorganic vapor phase epitaxy on InP(001) using tertiarybutylarsine

Cited by 17 publications

References 27 publications

Degradation of III–V Quantum Dot Lasers Grown Directly on Silicon Substrates

Degradation of III–V Quantum Dot Lasers Grown Directly on Silicon Substrates

Inverted metamorphic AlGaInAs/GaInAs tandem thermophotovoltaic cell designed for thermal energy grid storage application

The effect of threading dislocations on optical absorption and electron scattering in strongly mismatched heteroepitaxial III V compound semiconductors on silicon

Contact Info

Product

Resources

About