Student Paper Award Announced!!

Session Index

Solid State Lighting

Poster Session 2
Thursday, Dec. 4, 2014  16:40-17:50
Chair:
Room:
Notes:
Paper No.  2014-Thu-P0802-P001
Rong-Ci Hong Steady State Analysis of the Thermal Resistance for Multi-chip LED
Rong-Ci Hong,Shang-Ping Ying,Huan-Yu Chien,

Abstract—This study investigated the thermal resistance measurement proposed by NIST to access the thermal resistance of multi-chip LEDs and the relation between the thermal resistances of single chip and the chip in the multi-chip LEDs. It is found that the thermal resistance of the chip in four-chip 7070 LED with one chip power on is lower than the measured thermal resistance of the four-chip 7070 with all chips power on. The low temperature contribution of the chips nearby the chip measured for the thermal resistance is resiponsible fot the low thermal resistance for the four-chip 7070 LED.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P004
Cheng-chin Chen Greatly Improved Efficiency Droop for InGaN-Based Green Light Emitting Diodes by Quaternary Content Superlattice Electron Blocking Layer
Cheng-chin Chen,Bing-Cheng Lin,An-Jye Tzou,Chun-Yen Chang,Hao-Chung Kuo,

We presented a low efficiency droop behavior green light emitting diodes (LEDs) with a quaternary content InAlGaN/GaN superlattice electron blocking layer (SL-EBL). The light output power shows a 57% enhancement and only 30% efficiency droop, which is attributed to a smooth band bending with a uniform carrier distribution.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P005
huan-Yu Chien The Optical characteristics of PC-LEDs with Different Phosphor Concentrations and Leadframe Reflectivity
huan-Yu Chien,Shang-Ping Ying,Rong-Ci Hong,

This study proposes the effects of phosphor concentration and leadframe reflectivity on the pc-LEDs manufactured by dispensing method. The simulated results show the luminous flux increases as the phosphor concentration increasin It is also found that the CCT of the pc- LEDs decreases as the phosphor concentration increasing.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P008
Jian-Yu Shen Spectral of phosphor-conversion light-emitting diodes for ultimate color rendering
Jian-Yu Shen,Shang-Ping Ying,Tzung-Te Chen,

We proposed the relation between the chromaticity of two phosphors pc-LEDs and shingle phosphor white pc-LEDs in this study. The blue chip, green and red phosphors are used to fabricate pc-LEDs. It is found that the chromatic coordinate of the LEDs with two phosphor should relate to the LEDs with single phosphor.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P009
Xinhui Chen Numerical Study of current spreading and light extraction in deep UV light emitting diode
Xinhui Chen,Yuh-Renn Wu,

The current crowding effect in AlGaN 275 nm deep UVLEDs has been investigated using 2D drift diffusion solver and Monte Carlo ray-tracing method. Optimized condition for both lateral and vertical structure is presented here by changing the spacing between 2 fingers. Graphene as contact layer also has been discussed in this paper.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P010
Huan-Yu Chien The Optical characteristics of PC-LEDs with Different Phosphor Concentrations and Leadframe Reflectivity
Huan-Yu Chien,Shang-Ping Ying,Rong-Ci Hong,

This study proposes the effects of phosphor concentration and leadframe reflectivity on the pc-LEDs manufactured by dispensing method. The simulated results show the luminous flux increases as the phosphor concentration increasin It is also found that the CCT of the pc-LEDs decreases as the phosphor concentration increasing.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P011
I-Hsin Lu Modeling for Carrier Transportation in Organic Light-emitting Diode by Considering Effective Tail States
I-Hsin Lu,Yuh-Renn Wu,

We developed the 1D Poisson and drift-diffusion Solver by considering the effective tail states and field-dependent mobility to simulate the organic materials, such as NPB or TAZ. With the obtained tail state distribution and the field dependent mobility model, we applied this result in modeling organic light emitting diodes.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P012
Lin Huang-Yu Improvement the color uniformity of white LED by Distributed Bragg reflector structure
Lin Huang-Yu,Chen Kuo-Ju,Wang Sheng-Wen,Lin Chien-Chung,Wang Kuan-Yu,Li Jie-Ru,Chen Huang-Ming,Kuo Hao-chung,

This study demonstrates the application of DBR structure into the remote phosphor structure to improve the angular CCT deviation in white light-emitting diodes (WLEDs). In the experiment, the LED device with DBR structure yielded nice color uniformity that the CCT deviation can be improved from 1758K to 280K.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P013
Chih-Hao Li Electrode Pattern Design for GaN Vertical Light Emitting Diodes on Nano-patterned Si Substrates
Chih-Hao Li,

Optimized electrode patterns of vertical GaN-based light emitting diodes are designed on nanoscale patterned Si substrates. By introducing the device parameters reported from literatures, a uniform current spreading distribution is obtained from our designed electrodes.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P014
Hsin-Jen Chen Bipolar Host for an Efficient Blue Phosphorescence Organic Light-Emitting Diode
Tien-Lung Chiu,Hsin-Jen Chen,Yu-Hsuan Hsieh,Man-kit Leung,Chi-Feng Lin,Jiun-Haw Lee,

A new bipolar material, CbzOXD, was synthesized to be the host of emitting layer doped with FIrpic inside an efficient blue phosphorescence organic light-emitting diode. The device showed the maximum efficiency performance, e.g. current efficiency of 25.1 cd/A, power efficiency of 16.8 lm/W and external quantum efficiency of 12%.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P015
Chian-Yu Chen Failure Origins of AlGaN/GaN Light Emitting Diodes by Reverse-bias Water Vapor Stress
Hsiang Chen,Chian-Yu Chen,Yun-Yang He,Shang-Ren Lin,Kun-Min Hsieh,Min-Han Lin,Ba Syuan Siao,Huan-Yu Shen,Chin-Pang Chen,Li-Chen Chu,Yu-Cheng Chu,

Resolving failure origins of AlGaN/GaN light emitting diodes (LED) has received intensive study recently. In this research, reverse-bias emissions and deformation of the contact near the surface have been observed in stressed devices moisture conditions. We performed detailed studies on forward and reverse I-V, breakdown current profiles, and optical and material observations to gain insight to failure origins of AlGaN/GaN LEDs. Our studies indicate that the deformation of the contact may cause the device failure.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P016
Shun-Yuan Huang The Material of Encapsulation of light-emitting diodes characteristic for short wavelength in high temperature aging test
Shun-Yuan Huang,Yii-Der Wu,Jau-Sheng Wang,

The light-emission diode has a good development in shorter wavelength, the major encapsulates material has a problem for the optics. Therefore we develop a novel material to encapsulate the ultraviolet-light emission diode module. The material of Sol-Gel has higher transmittance for the ultraviolet band and higher thermal stability than silicone.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P017
Yifan Liu Simulation on Parameters with Tracepro Based on New Remote Phosphor LED Design
Liu Yifan, Liang Hengmao, Lv Weiwen, Liu Jun, Wu Yiping,

The article focuses on simulation of remote phosphor LED with Tracepro. After designing three different models, we corroborate the circular plate structure is the most efficient. Based on this, we investigated the influence of concentration and thickness of phosphor on intensity and color temperature; hence figuring out optimal parameter settings.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P018
Lin Huang-Yu Improvement the color uniformity of white LED by Distributed Bragg reflector structure
Lin Huang-Yu,Chen Kuo-Ju,Wang Sheng-Wen,Wang Kuan-Yu,Lin Chien-Chung,Li Jie-Ru,Chen Huang-Ming,Kuo Hao-chung,

This study demonstrates the application of DBR structure into the remote phosphor structure to improve the angular CCT deviation in white light-emitting diodes (WLEDs). In the experiment, the LED device with DBR structure yielded nice color uniformity that the CCT deviation can be improved from 1758K to 280K.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P019
Yu-Chi Wang High-Reliability of Warm-White LEDs Containing Composite Silica Photonic Crystals
Yu-Chi Wang,Chun-Feng Lai,

In this study, we demonstrated a reduced phosphor use technique that applied to white light-emitting diodes (WLEDs) containing composite silica colloidal photonic crystals (c-SCPhCs) for developing the warm-white LEDs (w-WLEDs). Thus, WLEDs containing c-SCPhCs conducted a reliability analysis test that applied a temperature/relative-humidity at 85 °C/85 with 120 mA for 2500 h, determining no visible degradation in optical performance. We implemented a novel, inexpensive technique to produce high luminous flux w-WLEDs for use as a residential light source.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P020
Jia-Yu Zeng Excellent Color-Rendering Index Candlelight LEDs Containing Composite Photonic Crystals
Jia-Yu Zeng,Chun-Feng Lai,

In this study, a technique that saved phosphor use was applied to warm white light-emitting diodes containing composite colloidal photonic crystals to develop the candlelight that exhibits a high luminous flux (52 lm) and an excellent color-rendering index (CRI; 94). A novel, inexpensive technology was implemented to produce high-CRI candlelight LEDs for use as a residential light source.

 Preview abstract
 
Paper No.  2014-Thu-P0802-P021
Yi Ting He Internal quantum efficiency droop of GaN LED
Yi Ting He,Min Gong,Zhi Ren Qiu,Bao Ping Zhang,Zhe Chuan Feng,

Internal quantum efficiency droop of GaN LED

 Preview abstract