Results 241 to 250 of about 7,775,448 (290)
Some of the next articles are maybe not open access.
Light Extraction of High-Efficient Light-Emitting Diodes
2017This chapter deals with methods for fabricating high-efficient light-emitting diodes (LEDs) with higher light extraction efficiency (LEE). Some LED prototypes are then reviewed to investigate how their performance was enhanced by utilizing a variety of chip processes.
Ja-Yeon Kim +6 more
openaire +1 more source
Effects of light extraction efficiency to the efficiency droop of InGaN-based light-emitting diodes
Journal of Applied Physics, 2013Light extraction efficiency (LEE) droop as an important factor contributing to the efficiency droop of InGaN-based light-emitting diodes (LEDs) has been demonstrated and investigated in detail. The LEE droop effect is induced by the spatial dependence of the extraction efficiency of photons inside of the LED devices and the aggravating crowding effect ...
Yiyun Zhang +9 more
openaire +1 more source
2013
We describe simulations of the light extraction efficiency (LEE) as a function of the major materials parameters and geometries in the three main LED structures used today, namely nitride LEDs on GaN substrates, on patterned sapphire substrates and flip chip nitride LEDs. We use ray tracing simulations of LEDs to show how the various extraction schemes
C. Lalau Keraly +3 more
openaire +1 more source
We describe simulations of the light extraction efficiency (LEE) as a function of the major materials parameters and geometries in the three main LED structures used today, namely nitride LEDs on GaN substrates, on patterned sapphire substrates and flip chip nitride LEDs. We use ray tracing simulations of LEDs to show how the various extraction schemes
C. Lalau Keraly +3 more
openaire +1 more source
The Light Extraction Efficiency for DUV LEDs
2019DUV LEDs have very low light extraction efficiency (LEE), which is caused by the unique optical polarization and the optically absorptive semiconductor and metal layers. This chapter reviews and analyzes the approaches that have ever been used to improve the LEE.
Zi-Hui Zhang +3 more
openaire +1 more source
Improving light extraction efficiency of PhC LED
2016 11th International Conference on Advanced Semiconductor Devices & Microsystems (ASDAM), 2016In this work we focus on improving light extraction efficiency of PhC LED. Studied LED structure was based on GaAs/AlGaAs material system. 1D PhC was patterned on the top of the LED structure with 3 different periods (500 nm, 600 nm, 800 nm). Several studies confirm improving light extraction efficiency of studied LED structure using PhC patterning. In
P. Hronec +4 more
openaire +1 more source
High-efficiency light injection and extraction using fiber bending
Optical Fiber Communication Conference, 2017We achieve a temporary optical coupler that injects/extracts light into/from a fiber with high efficiency by using fiber bending. We demonstrate experimentally that extraction efficiency is improved by using a double-clad fiber.
Takui Uematsu +4 more
openaire +2 more sources
Light Extraction Efficiency of the LED with Guide Layers
Japanese Journal of Applied Physics, 1976An LED with guide layers, which is similar to the DH-structured diode, is devised. By calculating the efficiency ee of extracting the light from the active region to the diode facet within a certain solid angle, we have obtained the following conclusions: (1) If the absorption coefficient αa of the active region is large, ee for the LED with guide ...
openaire +1 more source
On the Light Extraction Efficiency for III-Nitride-Based Light-Emitting Diodes
2019Considering the large contrast of the refractive index between the air and the III-nitride semiconductor layer, the external quantum efficiency for III-nitride-based light-emitting diodes is strongly influenced by the light extraction efficiency. This chapter reviews the current status for the technologies that have been adopted thus far to improve the
Zi-Hui Zhang +4 more
openaire +1 more source
Physics of light extraction efficiency in planar microcavity light-emitting diodes
1999We use the modifications of spatial mode distributions in planar microcavities to address the issue of light outcoupling in devices such as LEDs. Whereas detailed calculations are needed to fully model and optimize the structures, we show that a simple picture can be obtained that clarifies the main physical effects of the microcavity.
openaire +1 more source