模擬、與分析 - 郭艷光

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藍光雷射實驗室簡介與
藍光發光二極體之設計、
模擬、與分析
郭艷光Yen-Kuang Kuo
彰化師大物理系暨光電科技研究所教授
國立彰化師範大學理學院院長
電子郵件: [email protected]
網頁: http://ykuo.ncue.edu.tw
郭艷光 – 藍光雷射實驗室
 1997年12月底向彰化師大校長提出
「藍光雷射計畫」,提議研發半導
體雷射,獲得800萬元經費補助,
成立「藍光雷射實驗室」。
 除了半導體雷射之外,還帶領學生
從事發光二極體(LED)、有機發光
二極體(OLED)、太陽能電池(Solar
Cell)的研究工作。
2
實驗室主要的研究能量

本實驗室早期之研究主要利用光激螢光法與電激螢
光法來研究半導體雷射(LD)與發光二極體(LED)等
光電半導體材料之光學與電子特性。此外,本實驗
室之光學系統亦可量測穿透/吸收/反射光譜與拉曼
光譜。

在光電實驗之外,我們也並行從事雷射二極體、發
光二極體、有機發光二極體(OLED)、與太陽能電
池的數值模擬與分析,使用的軟體包括LASTIP、
PICS3D、APSYS、SimuLED、SimuLAMP等。

目前研究主要以『系統設計與模擬分析』為主。
3
實驗室主要的軟體資源
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LASTIP模擬軟體 (側射型半導體雷射 …)
(Crosslight Software Inc., Canada)
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PICS3D模擬軟體 (面射型半導體雷射、DFB雷
射、Self-Pulsation雷射 …) (Crosslight)
APSYS模擬軟體 (LED、 OLED 、太陽能電池
、RC-LED、光偵測器、HEMT …) (Crosslight)
SimuLED模擬軟體 (LED及LD元件特性,由俄
羅斯STR Group公司提供,台灣皮托科技代理)
SimuLAMP模擬軟體 (LED等發光元件之封裝,
由俄羅斯STR Group公司提供,台灣皮托科技
代理)
4
實驗室主要的硬體設備
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光學桌 (2台)
氦氖雷射 (632.8nm紅光光源)
氬離子雷射 (488nm藍光, 514.5nm綠光, 351.1nm紫外線光源)
Nd:YAG雷射 (EO Q-switched, 1064/532/355/266 nm)
單色分光儀與鹵素燈寬頻光源 (穿透, 吸收, 反射頻譜測量)
波長選擇器 (Birefringent Filter)
發光二極體(LED/OLED)亮度與I-V特性測量儀 (PC-controlled)
半導體雷射/發光二極體電流源 (PC-controlled current source)
密閉式低溫系統 (10K ~ 325K)
液態氮冷卻電荷耦合器(CCD)光偵測器 (1340×100 Pixels)
鎖相放大器 (Lock-in Amplifier)
光電增倍管 (Photo-Multiplier Tube)
功率計 (Power Meters) (3組)
半導體摻雜濃度測量儀 (ECV, 適用於GaN系統)
快速示波器 (500 MHz Bandwidth, 5 GHz Sampling Rate)
快速光偵測器 (Response time ~ 1 ns)
5
光激螢光(Photoluminescence)系統簡介
待測元件
波長為351.1 nm, 488.0 nm, 514.5 nm, …
氬離子雷射
低溫系統:
10 K ~ 325 K
相位截光器
穿透量測
入口
光纖
單色分光儀(ARC
SP-750)
光電增倍
管
CCD
(Princeton)
控制
電腦
鎖相放大器
6
郭艷光開設之研究所課程
 99(上)授課內容:
(1) 半導體光學 (物理系與光電所碩博合開選修)
(2) 半導體雷射特論 (物理系與光電所碩博合開選修)
 99(下)預定授課內容:
(1) 半導體雷射 (物理系與光電所碩博合開選修)
(2) 發光二極體特論 (物理系與光電所碩博合開選修)
7
同學們離開學校之
前,必須具備:
專業、英語、電腦
網路三項重要能力
成功的秘訣:
要有好的人格特質!
有時候,
吃虧就是佔便宜。
及早規劃人生,
船到橋頭自然直
的觀念可能會讓
你辛苦一輩子
高學位、名校
不再是生活的
保障,實力決
定一切!
學術能力強、具獨立研究能力
的人到台清交成進修,可能可
以得到超乎常人的成就;
研究所的訓練,關鍵在指導
教授。留下來彰化師大唸碩士
班、博士班,說不定可以得到
更好的訓練。
申請大專生國科會計畫需
要有好成績做後盾,留下
來唸碩士班、博士班不需
要考慮成績好壞,只要肯
拼,每個人都會有屬於自
己的一片天空。
直攻光電科技研究所與物
理研究所博士班的資格:
(1) 碩士班一年級學生,
(2) 大學部四年級學生。
註:國科會千里馬計畫可以提供獎學
金給優秀博士生至國外大學進修。
如果你對發光二極體
(LED)、OLED、半導
體雷射、太陽能電池
的研發有興趣,歡迎
你(妳)加入藍光雷射
實驗室的大家庭!
國科會專題與產學合作計畫
 三五族與氮化物光電半導體元件之實驗及
模擬分析(1/3) (NSC 99-2119-M-018-002MY3)
 高效率藍光與近紫外光InGaN LED之模擬
與設計 (晶元光電股份有限公司合作計畫)
 氮化鋁鎵深紫外光發光二極體元件之模擬
分析與設計 (99年大專學生參與國科會專題
研究計畫,NSC 99-2815-C-018-008-M)
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近年來主要的研究主題
 Light-Emitting
Diodes (LED)
 Laser Diodes & VCSEL
 Light-Emitting Diodes (OLED)
 Solar Cells (Si & III-V)
 Others (III-N Band Structures &
Bowing Parameters, Solid-State
Lasers, etc.) (數篇SCI論文被引用
數在10次以上)
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模擬軟體在學術與產業上的應用
模擬軟體可以協助研究人員設計元件,並
且探討元件的光學與電子特性。
 如果有實驗結果可以進行比較分析,我們
通常會調整可用的Free Parameters,讓模
擬結果可以盡可能與實驗結果一致。
 接下來,我們可以提出各種可以改善元件
特性或操作性能的方法,進行模擬分析。
 經過幾次的調整與校正之後,模擬軟體即
可成為元件設計的重要輔助工具,既可省
下大量嘗試錯誤的時間,並能節省研發經
費,取得研發與量產的先機。
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APSYS模擬軟體
(Advanced Physical Models of Semiconductor Devices)
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LED、OLED、與Solar Cell等光電半導體
元件的設計、模擬、與分析,均可以借助
APSYS模擬軟體來執行。

APSYS可以經由解Poisson’s equation、
current continuity equation、carrier energy
transport equation、以及quantum
mechanical wave equation等方程式,求得
光電半導體元件的各種光學與電子特性。
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APSYS亦使用Ray-Tracing技術,分析由元
件所輸出之光強度以及光場隨角度之分佈
情形。
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APSYS所能提供的資訊
 光功率-電流(L-I)與電流-電壓(I-V)圖
 電位、電場、電流分佈圖
 電子、電洞濃度分佈圖
 元件溫度分佈圖
 不同溫度、電流下之能帶圖
 二維光場分佈圖
 自發輻射頻譜對電流關係圖
 以上所有圖形對時間的變化關係
 以上所有圖形對溫度的變化關係
20
Examples of Simulations
Simulation
of LEDs
Simulation
of Laser Diodes
Simulation
of VCSELs
Simulation
of OLEDs
Simulation
of Solar Cells
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Simulation of LEDs
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After comparing, preferable designs of
the staggered QWs are In0.20Ga0.80N
(1.4 nm)–In0.26Ga0.74N (1.6 nm),
In0.21Ga0.79N (1.4 nm)–In0.25Ga0.75N
(1.6 nm), and In0.22Ga0.78N (1.5 nm)–
In0.24Ga0.76N (1.5 nm), which are
named as structure A, structure B,
and structure C, respectively.
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The effective potential height for holes in
the valence band of the InGaN/AlGaN
structure is lower than that of the
InGaN/GaN one (i.e., 0.255 eV vs. 0.282
eV) owing to the slighter polarization
effect in the last-barrier/EBL interface.
The effective potential height for the
electrons in the conduction band of the
InGaN/AlGaN structure becomes higher
than the other structure (i.e., 0.367 eV vs.
0.355 eV), which denotes the enhancement
of electron confinement.
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The light performance of the blue InGaN LEDs emitting in a spectral range
from 435 to 445 nm can be enhanced effectively when the conventional GaN
barrier layers are replaced by the low-indium-content In0.02Ga0.98N and
In0.05Ga0.95N barrier layers.
The light performance of the 445-nm LEDs with the In0.05Ga0.95N barrier layers
is improved due to the increased overlap of electrons and holes inside the QW
close to the p-side layers, which is the major source for radiative
recombination.
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The strong electric field caused by the
piezoelectric polarization charges at the
interface between the P-AlGaN and
barrier layer lowers the conduction
band energy in the last barrier. Our
calculation shows that the percentages 
of electron leakage current for the
LEDs with P-AlGaN and N-AlGaN are
46.1% and 4.5%, respectively, at 120
mA.
Besides the relatively uniform
distribution of holes in the QWs, the
sufficiently reduced electron leakage
current is also a major cause for the
improvement in efficiency droop.
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Simulation of Laser Diodes
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40
Simulation of VCSELs
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Simulation of OLEDs
46
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Simulation of Solar Cells
太陽能電池的模擬與分析

Investigation of current matching for
In0.49Ga0.51P/GaAs/Ge triple-juction tandem solar cell
3
GaAs
Ge
InGaP
Energy (eV)
2
1
0
-1
-2
0.67 eV
-3
10
11
1.424 eV
12
13
1.885 eV
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15
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Distance (m)
Band diagram
Schematic drawing of the solar cell structure
49
上中下三個Cells的I-V曲線
Device
Top cell
Middle cell
Bottom cell
2
Current density (mA/cm )
50
40
30
20
10
0
0
0.5
1
1.5
2
2.5
3
Voltage (V)
Device current is limited by the smallest current.
50
中間Cell的最佳厚度
…
2
17.00
16.99
3.8 µm
16.98
16.97
16.96
16.95
3
3.2
3.4
3.6
3.8
4
Middle cell base layer thickness (m)
2
Current density (mA/cm )
…
Change the thickness of middle
cell base layer.
Current density (mA/cm )
…

17.01
…

Change the thickness of middle
cell emitter layer when the base
layer thickness is fixed at 3.8 µm.
17.014
17.012
17.010
0.17 µm
17.008
17.006
17.004
17.002
0.1
0.12
0.14
0.16
0.18
0.2
Middle cell emitter layer thickness (m)
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上中兩個Cells的電流匹配
2
Sun light power
Current density (mA/cm )
23
Sun light power
at top cell
0.236 µm
22
21
Top cell
Middle cell
20
19
18
17
16
15
decay
0
0.2
0.4
0.6
0.8
Top cell base layer thickness (m)
Sun light power  Base layer thicknesses of middle
at middle cell
cell → 3.8 μm
 Emitter layer thicknesses of
middle cell → 0.17 μm
Base layer thickness of top cell
→ 0.236 μm
52
優化後的結構
Device
Top cell
Middle cell
Bottom cell
2
Current density (mA/cm )
50
40
30
20
10
0
0
0.5
1
1.5
2
2.5
3
Voltage (V)

Schematic drawing of optimized structure
The photon current
density of the device can be
improved by enhancing the
middle cell photon current
density.
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太陽能電池模擬與分析的結論
2
Current density (mA/cm )
20

15
10
5
Optimal structure
Original structure
0
0
0.5
1
1.5
2
2.5
Voltage (V)
3

The short-circuit current
density is improved due to
the achievement of current
match.
The short-circuit current
density is improved from
16.56 to 18.78 mA/cm2 and
the conversion efficiency is
increased by about 3%.
improved about 3%
54
Recent publication (I)
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Yen-Kuang Kuo, Jih-Yuan Chang, and Miao-Chan Tsai, “Enhancement in
hole injection efficiency of blue InGaN light-emitting diodes from reduced
polarization by some specific designs on electron blocking layer”, Optics
Letters, Accepted 4 September 2010. (SCI) [2008 Impact Factor = 3.772,
Ranked 4/64 in Optics]
Chih-Teng Liao, Miao-Chan Tsai, Bo-Ting Liou, Sheng-Horng Yen, and
Yen-Kuang Kuo, “Improvement in output power of a 460-nm InGaN lightemitting diode using staggered quantum well”, Journal of Applied Physics,
Accepted 8 July 2010. (SCI) [2008 Impact Factor = 2.201, Ranked 20/95 in
Physics, Applied Physics]
Yen-Kuang Kuo, Syuan-Huei Horng, Miao-Chan Tsai, Sheng-Horng Yen,
and Shu-Hsuan Chang, “Effect of normal and reversed polarizations on
optical characteristics of ultraviolet-violet InGaN laser diodes”, Optics
Communications, Vol. 283, Issue 19, pp. 3698–3702, 1 October 2010. (SCI)
[2008 Impact Factor = 1.552, Ranked 23/64 in Optics]
Jih-Yuan Chang, Miao-Chan Tsai, and Yen-Kuang Kuo, “Advantages of
blue InGaN light-emitting diodes with AlGaN barriers”, Optics Letters, Vol.
35, No. 9, pp. 1368–1370, 1 May 2010. (SCI) [2008 Impact Factor = 3.772,
Ranked 4/64 in Optics]
55
Recent publication (II)
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Yen-Kuang Kuo, Miao-Chan Tsai, Sheng-Horng Yen, Ta-Cheng Hsu, and YuJiun Shen, “Effect of p-type last barrier on efficiency droop of blue InGaN
light-emitting diodes”, IEEE Journal of Quantum Electronics, Vol. 46, No. 8,
pp. 1214–1220, August 2010. (SCI) [2008 Impact Factor = 2.413, Ranked 37/229
in Engineering, Electrical & Electronic]
Miao-Chan Tsai, Sheng-Horng Yen, and Yen-Kuang Kuo, “Carrier
transportation and internal quantum efficiency of blue InGaN light-emitting
diodes with p-doped barriers”, IEEE Photonics Technology Letters, Vol. 22, No.
6, pp. 374–376, 15 March 2010. (SCI) [2008 Impact Factor = 2.173, Ranked
12/64 in Optics]
Jun-Rong Chen, Yung-Chi Wu, Shih-Chun Ling, Tsung-Shine Ko, Tien-Chang
Lu, Hao-Chung Kuo, Yen-Kuang Kuo, and Shing-Chung Wang, “Investigation
of wavelength-dependent efficiency droop in InGaN light-emitting diodes”,
Applied Physics B: Lasers and Optics, Vol. 98, No. 4, pp. 779–789, March 2010.
(SCI) [2008 Impact Factor = 2.167, Ranked 13/64 in Optics]
Yen-Kuang Kuo, Syuan-Huei Horng, Sheng-Horng Yen, Miao-Chan Tsai, and
Man-Fang Huang, Published online 26 November 2009, “Effect of polarization
state on optical properties of blue-violet InGaN light-emitting diodes”, Applied
Physics A: Materials Science & Processing, Vol. 98, No. 3, pp. 509–515, 4
January 2010. (SCI) [2008 Impact Factor = 1.884, Ranked 30/95 in Physics,
Applied Physics]
56
Recent publication (III)
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Yen-Kuang Kuo, Jih-Yuan Chang, and Mei-Ling Chen, “Role of electron
blocking layer in III-nitride laser diodes and light-emitting diodes”, Proceedings
of SPIE, Vol. 7597, pp.759720-1–759720-9, Published online 25 February 2010.
(EI)
Shu-Hsuan Chang, Miao-Chan Tsai, Sheng-Horng Yen, Shu-Jeng Chang, and
Yen-Kuang Kuo, “Numerical simulation on high-efficiency GaInP/GaAs/InGaAs
triple-junction solar cells”, Proceedings of SPIE, Vol. 7597, pp.759721-1–75972112, Published online 25 February 2010. (EI)
陳俊榮、張誌原、郭艷光、盧廷昌、郭浩中、王興宗, “高亮度氮化鎵發光二極
體:高驅動電流下的屏障”, 電子月刊, 第16卷, 第6期, 第118至129頁, 2010年6月.
Yen-Kuang Kuo, Jih-Yuan Chang, Miao-Chan Tsai, and Sheng-Horng Yen,
“Advantages of blue InGaN multiple-quantum well light-emitting diodes with
InGaN barriers”, Applied Physics Letters, Vol. 95, No. 1, pp. 011116-1 - 011116-3,
Published online 10 July 2009. (SCI) [2008 Impact Factor = 3.726, Ranked 10/95
in Physics, Applied Physics]
Yen-Kuang Kuo, Miao-Chan Tsai, Sheng-Horng Yen, Ta-Cheng Hsu, and YuJiun Shen, “Enhancement of light power for blue InGaN light-emitting diodes by
using low-indium-content InGaN barriers”, IEEE Journal of Selected Topics in
Quantum Electronics, Vol. 15, No. 4, pp. 1115-1121, 5 August 2009. (SCI) [2008
Impact Factor = 2.518, Ranked 9/64 in Optics]
57
Recent publication (IV)
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Yen-Kuang Kuo, Miao-Chan Tsai, and Sheng-Horng Yen, “Numerical
simulation of blue InGaN light-emitting diodes with polarization-matched
AlGaInN electron-blocking layer and barrier layer”, Optics Communications,
Vol. 282, Issue 21, pp. 4252-4255, 1 November 2009. (SCI) [2008 Impact Factor
= 1.552, Ranked 23/64 in Optics]
Sheng-Horng Yen, Miao-Chan Tsai, Meng-Lun Tsai, Yu-Jiun Shen, Ta-Cheng
Hsu, and Yen-Kuang Kuo, “Effect of n-type AlGaN layer on carrier
transportation and efficiency droop of blue InGaN light-emitting diodes”,
IEEE Photonics Technology Letters, Vol. 21, No. 14, pp. 975-977, 15 July 2009.
(SCI) [2008 Impact Factor = 2.173, Ranked 12/64 in Optics]
Sheng-Horng Yen, Miao-Chan Tsai, Meng-Lun Tsai, Yu-Jiun Shen, Ta-Cheng
Hsu, and Yen-Kuang Kuo, Published online 26 June 2009, “Theoretical
investigation of Auger recombination on internal quantum efficiency of blue
light-emitting diodes”, Applied Physics A: Materials Science & Processing, Vol.
97, Issue 3, pp. 705-708, 4 November 2009. (SCI) [2008 Impact Factor = 1.884,
Ranked 30/95 in Physics, Applied Physics]
Miao-Chan Tsai, Sheng-Horng Yen, Shu-Hsuan Chang, and Yen-Kuang Kuo,
“Effect of spontaneous and piezoelectric polarization on optical characteristics
of ultraviolet AlGaInN light-emitting diodes”, Optics Communications, Vol.
282, Issue 8, pp. 1589-1592, 15 April 2009. (SCI) [2008 Impact Factor = 1.552,
Ranked 23/64 in Optics]
58
Recent publication (V)

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Jun-Rong Chen, Yung-Chi Wu, Tien-Chang Lu, Hao-Chung Kuo, Yen-Kuang
Kuo, and Shing-Chung Wang, “Numerical study on lateral mode behavior of
660-nm InGaP/AlGaInP multiple-quantum-well laser diodes”, Optical Review,
Vol. 16, No. 3, pp. 375–382, Published online 9 June 2009. (SCI) [2008 Impact
Factor = 0.545, Ranked 51/64 in Optics]
Yen-Kuang Kuo, Ying-Chung Lu, Miao-Chan Tsai, and Sheng-Horng Yen,
“Numerical simulation of 405-nm InGaN laser diodes with polarizationmatched AlGaInN electron-blocking layer and barrier layer”, Proceedings of
SPIE, Vol. 7211, 72111B-1 – 72111B-8, January 2009. (EI)
Bo-Ting Liou, Miao-Chan Tsai, Chih-Teng Liao, Sheng-Horng Yen, and YenKuang Kuo, “Numerical investigation of blue InGaN light-emitting diodes
with staggered quantum wells”, Proceedings of SPIE, Vol. 7211, pp. 72111D-1
– 72111D-8, January 2009. (EI)
Shu-Hsuan Chang, Chien-Yang Wen, Yi-Hsiang Huang, and Yen-Kuang Kuo,
“Numerical simulation on white OLEDs with dotted-line doped emitting
layers”, Proceedings of SPIE, Vol. 7213, 72131J-1 – 72131J-8, January 2009.
(EI)
59
Blue Laser Laboratory
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