Dependence of radiative efficiency and deep level defect incorporation on threading dislocation density for InGaN/GaN light emitting diodes

2012 ◽  
Vol 101 (16) ◽  
pp. 162102 ◽  
Author(s):  
A. Armstrong ◽  
T. A. Henry ◽  
D. D. Koleske ◽  
M. H. Crawford ◽  
K. R. Westlake ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Light Emitting Diodes ◽  
Deep Level ◽  
Threading Dislocation ◽  
Deep Level Defect ◽  
Light Emitting ◽  
Radiative Efficiency ◽  
Threading Dislocation Density

Yellow-green emission for ETS-LEDs and lasers based on a strained–InGaP quantum well heterostructure grown on a transparent, compositionally graded AlInGaP buffer

2002 ◽  
Vol 744 ◽  
Author(s):  
Lisa McGill ◽  
Juwell Wu ◽  
Eugene Fitzgerald
Keyword(s):  
Dislocation Density ◽  
Quantum Well ◽  
Gallium Phosphide ◽  
Light Emitting Diodes ◽  
Green Emission ◽  
Threading Dislocation ◽  
Peak Wavelength ◽  
Device Structure ◽  
Light Emitting ◽  
Threading Dislocation Density

ABSTRACTEpitaxial-transparent-substrate light emitting diodes with a primary emission peak at 590nm and a secondary peak at 560nm have been fabricated in the indium aluminum gallium phosphide (InAlGaP) system. The active layer consists of an undoped, compressively strained indium gallium phosphide (InGaP) quantum well on a transparent In0.22(Al0.2Ga0.8)0.78P/ ∇x[1nx(Al0.2Ga0.8)1-xP] /GaP virtual substrate. Theoretical modeling of this structure predicts an accessible wavelength range of approximately 540nm to 590nm (green to amber). Emission with a peak wavelength of 570nm has been observed via cathodoluminescence studies of undoped structures with a quantum well composition of In0.35Ga0.65P. Light emitting diodes have been fabricated utilizing simple top and bottom contacts. The highest LED power of 0.18μW per facet at 20mA was observed for a quantum well composition of In0.32Ga0.68P and a bulk threading dislocation density on the order of 7×106 cm-2. The spectrum of this device was composed of two peaks: a weak peak at the predicted 560nm wavelength and a stronger peak at 590nm. Based upon superspots present in electron diffraction from the quantum well region, we believe that the observed spectrum is the result of emission from ordered and disordered domains in the active region. The same device structure grown with a bulk threading dislocation density on the order of 5×107 cm-2 exhibited an identical spectral shape with a reduced power of 0.08μW per facet at 20mA. For a quantum well composition of In0.37Ga0.63P and an overall threading dislocation density on the order of 5×107 cm-2, a single peak wavelength of 588nm with a power of 0.06μW per facet at 20mA was observed.

scholarly journals Quantitative and depth-resolved deep level defect distributions in InGaN/GaN light emitting diodes

2012 ◽  
Vol 20 (S6) ◽  
pp. A812 ◽  
Author(s):  
A. Armstrong ◽  
T. A. Henry ◽  
D. D. Koleske ◽  
M. H. Crawford ◽  
S. R. Lee
Keyword(s):  
Light Emitting Diodes ◽  
Deep Level ◽  
Deep Level Defect ◽  
Light Emitting

High Efficiency Uv Emitter Using High Quality GaN/AlxGa1−xN Multi-Quantum Well Active Layer

2000 ◽  
Vol 639 ◽  
Author(s):  
M. Iwaya ◽  
S. Terao ◽  
T. Ukai ◽  
R. Nakamura ◽  
S. Kamiyama ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Quantum Wells ◽  
High Efficiency ◽  
Light Emitting Diode ◽  
Threading Dislocation ◽  
Light Emitting ◽  
Si Doping ◽  
Threading Dislocation Density ◽  
Pl Intensity ◽  
Multi Quantum Well

ABSTRACTWe investigated temperature dependence of the photoluminescence (PL) efficiency of GaN/Al0.08Ga0.92N multi-quantum wells (MQWs) with variations of Si-doping condition and threading dislocation density. Si-doping in the GaN/Al0.08Ga0.92N MQWs, especially in the barrier layer improves the PL efficiency. In addition, reduction of threading dislocation density also improves the PL intensity. The PL intensity of the GaN/Al0.08Ga0.92N MQW is drastically increased at least by a factor of 40, by a combination of the Si-doping and reduction of threading dislocation density. We fabricated a light emitting diode (LED) emitting at 357 nm using such a GaN/Al0.08Ga0.92N MQWs. Electro-luminescence intensity from the region with threading dislocation density of less than 108 cm−2 was much larger than that from the region with threading dislocation density of 6×109 cm−2.

High-Irradiance Degradation Studies of Metamorphic 1eV GaInAs Solar Cells

2012 ◽  
Vol 1432 ◽  
Author(s):  
Ryan M. France ◽  
Myles A. Steiner
Keyword(s):  
Solar Cells ◽  
Active Region ◽  
Dislocation Density ◽  
Dark Current ◽  
Degradation Mechanism ◽  
Control Cell ◽  
High Irradiance ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Degradation Studies

ABSTRACTInitial tests are performed regarding the degradation of lattice-mismatched GaInAs solar cells. 1eV metamorphic GaInAs solar cells with 1-2×106 cm-2 threading dislocation density in the active region are irradiated with an 808 nm laser for 2 weeks time under a variety of temperature and illumination conditions. All devices show a small degradation in Voc that is logarithmic with time. The absolute loss in performance after 2 weeks illuminated at 1300 suns equivalent and 125°C is 7 mV Voc and 0.2% efficiency, showing these devices to be relatively stable. The dark current increases with time and is analyzed with a two-diode model. A GaAs control cell degrades at the same rate, suggesting that the observed degradation mechanism is not related to the additional dislocations in the GaInAs devices.

Relationship between misfit-dislocation formation and initial threading-dislocation density in GaInN/GaN heterostructures

2015 ◽  
Vol 54 (11) ◽  
pp. 115501 ◽  
Author(s):  
Motoaki Iwaya ◽  
Taiji Yamamoto ◽  
Daisuke Iida ◽  
Yasunari Kondo ◽  
Mihoko Sowa ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Misfit Dislocation ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Dislocation Formation

Enhanced reduction in threading dislocation density in Ge grown on porous silicon during annealing due to porous buffer reconstruction

2015 ◽  
Vol 213 (1) ◽  
pp. 96-101
Author(s):  
G. Calabrese ◽  
S. Baricordi ◽  
P. Bernardoni ◽  
D. De Salvador ◽  
M. Ferroni ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Dislocation Density ◽  
Threading Dislocation ◽  
Threading Dislocation Density
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