Optical performance of efficient blue/near UV nitropyridine-conjugated anthracene (NAMA) based light emitting diode

2016 ◽  
Vol 31 ◽  
pp. 25-30 ◽  
Author(s):  
Songül Fiat Varol ◽  
Serkan Sayin ◽  
Serkan Eymur ◽  
Ziya Merdan ◽  
Derya Ünal
Keyword(s):  
Light Emitting Diode ◽  
Optical Performance ◽  
Light Emitting

scholarly journals Optical performance of top-down fabricated InGaN/GaN nanorod light emitting diode arrays

2011 ◽  
Vol 19 (25) ◽  
pp. 25528 ◽  
Author(s):  
Qiming Li ◽  
Karl R. Westlake ◽  
Mary H. Crawford ◽  
Stephen R. Lee ◽  
Daniel D. Koleske ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Optical Performance ◽  
Top Down ◽  
Light Emitting

scholarly journals Impact of severe cracked germanium (111) substrate on aluminum indium gallium phosphate light-emitting-diode’s electro-optical performance

Open Physics ◽  
2016 ◽  
Vol 14 (1) ◽  
pp. 253-260
Author(s):  
Luruthudass Annaniah ◽  
Mutharasu Devarajan
Keyword(s):  
Crack Formation ◽  
Light Emitting Diode ◽  
Temperature Cycle ◽  
Optical Performance ◽  
Light Emitting ◽  
Indium Gallium ◽  
Reliability Performance ◽  
Product Specification ◽  
Gallium Phosphate

AbstractCracked die is a serious failure mode in the Light Emitting Diode (LED) industry – affecting LED quality and long-term reliability performance. In this paper an investigation has been carried out to find the correlation between severe cracked germanium (Ge) substrate of an aluminum indium gallium phosphate (AlInGaP) LED and its electro-optical performance after the Temperature Cycle (TC) test. The LED dice were indented at several bond forces using a die bonder. The indented dice were analysed using a Scanning Electron Microscope (SEM). The result showed that severe cracks were observed at 180 gF onward. As the force of indentation increases, crack formation also becomes more severe thus resulting in the chipping of the substrate. The cracked dies were packaged and the TC test was performed. The results did not show any electro-optical failure or degradation, even after a 1000 cycle TC test. Several mechanically cross-sectioned cracked die LEDs, were analysed using SEM and found that no crack reached the active layer. This shows that severely cracked Ge substrate are able to withstand a −40°C/+100°C TC test up to 1000 cycles and LED optical performance is not affected. A small leakage current was observed in all of the cracked die LEDs in comparison to the reference unit. However, this value is smaller than the product specification and is of no concern.

Impact of the Phosphors on the Conformal Coating LED by Optical Simulation

2013 ◽  
Vol 834-836 ◽  
pp. 1167-1171
Author(s):  
Yu Bing Gong ◽  
Ruan Ji Tian
Keyword(s):  
Concentration Distribution ◽  
Light Emitting Diode ◽  
Luminous Flux ◽  
Color Temperature ◽  
Optical Simulation ◽  
Optical Performance ◽  
Phosphor Layer ◽  
Light Emitting ◽  
Conformal Coating ◽  
Color Uniformity

The conformal coating phosphor converted light emitting diode (LED) is one of the important high power white LED. The thickness, concentration and concentration distribution of the phosphor layer has a critical influence on the LED optical performance. Previous literature mainly focus on the luminous flux of the LED. Few are involved with the relationship between the concentration and the correlated color temperature (CCT), and angular color uniformity (ACU) of LED. Based on the ray-tracing simulation, the luminous flux, CCT and ACU affected by the phosphor thickness, concentration and concentration distribution were obtained and studied. The results provide effective references for the phosphor coating process design and optical performance analysis of conformal coating LED.

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