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

Electrical Measurement of Recombination Lifetime in Blue Light Emitting Diodes

2004 ◽  
Vol 829 ◽  
Author(s):  
M. A. Awaah ◽  
R. Nana ◽  
K. Das
Keyword(s):  
Blue Light ◽  
Light Emitting Diodes ◽  
Deep Level ◽  
Electrical Measurement ◽  
High Concentration ◽  
Recombination Lifetime ◽  
Light Emitting ◽  
Radiative Processes ◽  
Current Voltage ◽  
Capacitance Voltage

ABSTRACTA recombination lifetime of approximately 25 ns was extracted from measured reverse recovery storage times in AlGaN/GaN/AlGaN double heterojunction blue light emitting diodes. This experimentally determined lifetime is expected to arise from a combination of radiative and non-radiative processes occurring in the diodes. The non-radiative processes are likely to be due the presence of a high concentration deep-states as identified from the current-voltage and capacitance-voltage measurements. Current-voltage characteristics of these diodes were highly non-ideal as indicated by high values of the ideality factor ranging from 3.0 – 7.0. Logarithmic plots of the forward characteristics indicated a space-charge-limited-current (SCLC) conduction in presence of a high density of “deep-level states” in the active region of the diodes. An analysis of these characteristics yielded an approximate density of these deep-level states as 2 × 1017/cm3. The density of deep-states extracted from capacitance-voltage measurements were in good agreement with that obtained from current-voltage measurements.

Effect of deep-level states on current-voltage characteristics and electroluminescence of blue and UV light-emitting diodes

2010 ◽  
Vol 207 (6) ◽  
pp. 1489-1496 ◽  
Author(s):  
R. Nana ◽  
P. Gnanachchelvi ◽  
M. A. Awaah ◽  
M. H. Gowda ◽  
A. M. Kamto ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Deep Level ◽  
Uv Light ◽  
Light Emitting ◽  
Current Voltage ◽  
Current Voltage Characteristics

Electrical and Optical Characterisation of Homojjunction Gallium Nitride Light Emitting Diodes

1997 ◽  
Vol 482 ◽  
Author(s):  
G M Laws ◽  
J Morgan ◽  
G B Ren ◽  
I Harrison ◽  
E C Larkins ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Full Width Half Maximum ◽  
Light Emitting Diodes ◽  
Deep Level ◽  
Deep Level Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Light Emitting ◽  
Current Voltage ◽  
Current Voltage Characteristics

AbstractWe report on the fabrication and characterisation gallium nitride light emitting diodes (LEDs) grown by molecular beam epitaxy on (0001) oriented sapphire and (111)B GaAs substrates. The current voltage characteristics of the devices grown on sapphire show turn on voltages of between 4 and 5V with large on-series resistance of 600Ω; for corresponding devices grown on GaAs these parameters are between 6 and 7V and 150 Ω, respectively.Room temperature electroluminescence (EL) spectra from the GaN LEDs ,grown on sapphire substrates, show a dominant emission at 3.2 eV (397nm) with a full width half maximum (FWHM) of 335 meV which is attributed to free electron to acceptor transitions (e, A−Mg). A broad low intensity deep level emission is also observed centred at 2.4 eV (506nm). The peak of the EL from the devices grown on GaAs is at 3.1eV rather than 3.2eV. The differences between the two sets of devices are probably caused by the different device geometry.Preliminary results show that an “annealing” effect caused by electrical stressing resulted in an improvement of the EL spectra. The stressed samples show an increase in the near band edge emission intensity, a 20meV reduction in the FWHM and a significant reduction in the intensity of the deep level emission. The devices have a large 1/f noise contribution which does not appear to change after electrical stressing.

Room and Cryogenic Temperature Operation of 280 nm Deep Ultraviolet Light Emitting Diodes

2002 ◽  
Vol 743 ◽  
Author(s):  
Maxim Shatalov ◽  
Vinod Adivarahan ◽  
Jian Ping Zhang ◽  
Ashay Chitnis ◽  
Shuai Wu ◽  
...  
Keyword(s):  
Ultraviolet Light ◽  
Radiative Recombination ◽  
Light Emitting Diodes ◽  
Deep Level ◽  
Optical Power ◽  
Light Emitting ◽  
Spectral Performance ◽  
Order Of Magnitude ◽  
Deep Ultraviolet ◽  
Ultraviolet Light Emitting Diodes

ABSTRACTWe present a study of the electrical and optical characteristics of 280 nm emission deep ultraviolet light emitting diodes (LED) at room and cryogenic temperatures. At low bias the defect assisted carrier tunneling primarily determines the current conduction. The room-temperature spectral performance and optical power are limited mostly by pronounced deep level defect assisted radiative and non-radiative recombination as well as poor electron confinement in the active region. At temperatures below 100 K the electroluminescence peak intensity increases by more than one order of magnitude due to suppression of non-radiative recombination channels indicating that with a proper device design and improved material quality, milliwatt power 280 nm LED are viable.

Sign in / Sign up

Export Citation Format

Share Document