Effects of active layer thickness on Er excitation cross section in GaInP/GaAs:Er,O/GaInP double heterostructure light-emitting diodes

2003 ◽  
Vol 340-342 ◽  
pp. 309-314 ◽  
Author(s):  
A. Koizumi ◽  
Y. Fujiwara ◽  
A. Urakami ◽  
K. Inoue ◽  
T. Yoshikane ◽  
...  
2011 ◽  
Vol 1342 ◽  
Author(s):  
Atsushi Nishikawa ◽  
Naoki Furukawa ◽  
Dong-gun Lee ◽  
Kosuke Kawabata ◽  
Takanori Matsuno ◽  
...  

ABSTRACTWe investigated the electroluminescence (EL) properties of Eu-doped GaN-based light-emitting diodes (LEDs) grown by organometallic vapor phase epitaxy (OMVPE). The thickness of the active layer was varied to increase the light output power. With increasing the active layer thickness, the light output power monotonically increased. The maximum light output power of 50 μW was obtained for an active layer thickness of 900 nm with an injected current of 20 mA, which is the highest value ever reported. The corresponding external quantum efficiency was 0.12%. The applied voltage for the LED operation also increased with the active layer thickness due to an increase in the resistance of the LED. Therefore, in terms of power efficiency, the optimized active layer thickness was around 600 nm. These results indicate that the optimization of the LED structure would effectively improve the luminescence properties.


2015 ◽  
Vol 3 (26) ◽  
pp. 6613-6615 ◽  
Author(s):  
Chun Sun ◽  
Yu Zhang ◽  
Sergii Kalytchuk ◽  
Yu Wang ◽  
Xiaoyu Zhang ◽  
...  

Monochrome LEDs and color graphical patterns were fabricated by changing the thickness and doping concentration of carbon dot layers.


2008 ◽  
Vol 22 (12) ◽  
pp. 1985-1995 ◽  
Author(s):  
M. P. BHOLE ◽  
E. P. SAMUEL ◽  
D. S. PATIL

Numerical simulation of optical confinement in simple double heterostructure of ZnO / Mg x Zn 1-x O and hybrid double heterostructure of Al x Ga 1-x N/ZnO have been carried out at 375 nanometer wavelength using MATLAB. Field distribution along the junction plane has been studied as a function of mole fractions of Mg and Al for different thickness of active layers. The spread of field has been estimated as a function of mole fractions and articulated as Full Width at Half Maximum (FWHM). It was found to be decreasing nonlinearly with increase of Mg mole fraction in simple heterostructure and increasing in a nonlinear manner with increase of Al mole fraction in hybrid heterostructure. FWHM deduced from our analysis was 0.265 micron for 9% and 0.16 micron for 30% Mg mole fraction. For hybrid heterostructure, FWHM values estimated were 0.13 micron and 0.1475 micron for corresponding Al mole fraction values of 9% and 30%, respectively. The narrower confinement of field intensity around the center of the active layer for the higher values of Mg mole fraction has been attributed to an increase of refractive index step between active and barrier layers. The confinement factor as a function of mole fractions and active layer thickness has been explored, and it was found to be increasing with active layer thickness. Our analysis explores the optical confinement of mode 0 in simple and hybrid heterostructures of ZnO .


2002 ◽  
Vol 744 ◽  
Author(s):  
Yasufumi Fujiwara ◽  
Atsushi Koizumi ◽  
Kentaro Inoue ◽  
Akira Urakami ◽  
Taketoshi Yoshikane ◽  
...  

ABSTRACTRoom-temperature Er-related electroluminescence (EL) properties have been investigated in Er,O-codoped GaAs (GaAs:Er,O) light emitting diodes (LEDs) grown by organometallic vapor phase epitaxy (OMVPE). Under forward bias, characteristic emission due to a luminescence center consisting of Er coordinated by O and As was clearly observed at room temperature, while the Er-related EL was undetectable under reverse bias. At lower current densities, the EL intensity increased linearly with the current density. Subsequently, the intensity exhibited a tendency to saturate at higher current densities. By analyzing the behavior with a fitting according to rate equations, the excitation cross section of Er ions due to current injection was determined to be approximately 10-15 cm2, which is by five orders in magnitude larger than that for optical excitation in Er-doped fiber amplifiers (10-20∼10-21 cm2).


2012 ◽  
Vol 61 (9) ◽  
pp. 098101
Author(s):  
Wu You-Zhi ◽  
Zhang Wen-Lin ◽  
Ni Wei-De ◽  
Zhang Cai-Rong ◽  
Zhang Ding-Jun

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