CN103515497A - 一种GaN基宽蓝光波长LED外延片及其应用 - Google Patents

一种GaN基宽蓝光波长LED外延片及其应用 Download PDF

Info

Publication number
CN103515497A
CN103515497A CN201310466986.7A CN201310466986A CN103515497A CN 103515497 A CN103515497 A CN 103515497A CN 201310466986 A CN201310466986 A CN 201310466986A CN 103515497 A CN103515497 A CN 103515497A
Authority
CN
China
Prior art keywords
gan
layer
blue light
light wavelength
ingan
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN201310466986.7A
Other languages
English (en)
Inventor
章勇
肖汉章
李正凯
罗长得
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
South China Normal University
Original Assignee
South China Normal University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by South China Normal University filed Critical South China Normal University
Priority to CN201310466986.7A priority Critical patent/CN103515497A/zh
Publication of CN103515497A publication Critical patent/CN103515497A/zh
Pending legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/04Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a quantum effect structure or superlattice, e.g. tunnel junction
    • H01L33/06Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a quantum effect structure or superlattice, e.g. tunnel junction within the light emitting region, e.g. quantum confinement structure or tunnel barrier
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/0004Devices characterised by their operation
    • H01L33/0008Devices characterised by their operation having p-n or hi-lo junctions
    • H01L33/0012Devices characterised by their operation having p-n or hi-lo junctions p-i-n devices
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/26Materials of the light emitting region
    • H01L33/30Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table
    • H01L33/32Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table containing nitrogen

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Led Devices (AREA)
  • Led Device Packages (AREA)

Abstract

本发明提供了一种GaN基宽蓝光波长LED外延片及其应用,其目的在于解决窄蓝光波长芯片激发黄光荧光粉封装白光LED的显色性不足的问题。该InGaN/GaN多量子阱宽蓝光波长LED外延结构从衬底开始,依次为GaN缓冲层、GaN本征层、n-GaN层、InGaN/GaN多量子阱层、p-AlGaN层和p-GaN层,其特点是在于InGaN/GaN多量子阱活性层的InGaN阱层的厚度从n-GaN到p-GaN方向逐渐增大,而GaN垒层厚度从n-GaN到p-GaN方向逐渐减小。并将这种宽蓝光波长芯片与黄光荧光粉封装成白光LED可以实现高显色性白光发射。

Description

一种GaN基宽蓝光波长LED外延片及其应用
技术领域
本发明涉及LED领域,更具体地,涉及一种GaN基宽蓝光波长LED外延片及其应用。
背景技术
 LED照明是未来照明领域的发展趋势,白光LED技术的发展则引领着LED照明走向未来。LED照明在对比传统的照明灯具时,具有体积小、发光效率高、发热量小、节能和长寿命等优势,然而,白光LED照明技术则仍然存在着不少问题,如显色性偏低等。 
    高质量的白光LED技术研究对于LED进一步取代传统灯具而成为主流产品的前进道路上显得尤为重要。现阶段,高显色性的白光LED方案主要有利用RGB三色芯片混合封装在一起形成白光LED、GaN基蓝光芯片加上RG荧光粉混合而成的白光LED、GaN基蓝光芯片加上YAG荧光粉和红光芯片补偿而成白光LED。这几种方案中,显色性都得到极大提高,但是,存在驱动复杂、混色不均、成本较高和红光荧光粉寿命短等问题。此外,无荧光粉的单芯片白光LED已有报道,主要是在同一个蓝宝石衬底上依次生长两种或三种InGaN/GaN多量子阱结构的LED,调节In组分来实现从蓝光到黄光的发射从而合成白光。但是,对于GaN基发光器件其发光效率一般在400~500 nm范围内的效率较高,随着发射波长向长波长方向增加,GaN基LED的发光效率逐渐减小,主要是因为高In组分的InGaN薄膜生长极其困难。当前蓝光加YAG:Ce黄光荧光粉的封装方案占据白光LED市场的主要份额。对于蓝光芯片加YAG:Ce荧光粉封装的白光LED,在高色温时具有高的显色指数,随低色温的减小,其显色性逐渐减小,当色温低于5500K时,显色一般低于70。
发明内容
本发明的目的在于提供一种GaN基宽蓝光波长LED外延片,从衬底开始,依次为GaN缓冲层、GaN本征层、n-GaN层、InGaN/GaN多量子阱层、p-AlGaN层和p-GaN层,所述的InGaN/GaN多量子阱活性层的InGaN阱层的厚度从n-GaN到p-GaN方向逐渐增大,所述的InGaN/GaN多量子阱活性层的GaN垒层厚度从n-GaN到p-GaN方向逐渐减小。靠近p-GaN侧GaN垒层厚度减小可以改善空穴注入,特别是与p-AlGaN电子阻挡层相邻的GaN垒层厚度减小能减弱GaN/p-AlGaN间的极化效应,最终可以减小电子的溢流而提高电子与空穴的复合几率。另一方面,靠近p-GaN侧厚的InGaN阱层可以增大量子阱内激子的寿命,从而增大空穴通过活性层到达n-GaN侧量子阱的几率来进一步改善电子与空穴在活性层的分布均匀,此外,不同阱层厚度可以实现发射峰的变化最终实现GaN基芯片的宽蓝光波长发射。
    所述的InGaN/GaN多量子阱层中的量子阱的数量为4~6。
    所述的InGaN阱层厚度,从n-GaN到p-GaN方向,由2 nm递增到3 nm,所述的GaN垒层厚度,从n-GaN到p-GaN方向,由16 nm递减到4 nm。
    所述的递增为等差递增,所述的递减为等差递减。
所述的InGaN阱层中In的摩尔量为Ga和In的总量的15~18%。
    所述的p-GaN层掺有受主Mg,所述的n-GaN层掺有施主Si。
    所述的衬底为蓝宝石、硅、SiC或GaN中的一种。
    更进一步,本发明提供一种白光LED,由GaN基宽蓝光波长芯片与黄光荧光粉结合封装而成,所述的GaN基宽蓝光波长芯片包含上述的GaN基宽蓝光波长LED外延片。。
    所述的白光LED的发射峰值的范围在550~590nm,所述黄光荧光粉为YAG:Ce+、硅酸盐、铝酸盐或氮化物中的一种。
该GaN基宽蓝光波长LED外延片的制备方法是通过MOCVD技术实现,包括下列步骤:
(1)采用AlGaInN系材料生长专用MOCVD,升温至1000~1100 ℃烘烤衬底5~10分钟。
(2)降温至480 ℃,在衬底上生长厚度为30 nm的GaN低温度缓冲层。
(3)升温至1050 ℃,生长厚度为2 μm的未掺杂GaN层。
(4)在1000~1100 ℃的温度下生长厚度2.0~4.0 μm的n-GaN层。
(5)将温度降至600~800 ℃,生长InGaN/GaN多量子阱活性层,周期数为4~6,InGaN阱层厚度从n-GaN到p-GaN方向由2 nm逐渐递增到3 nm,GaN垒层厚度从n-GaN到p-GaN方向16 nm逐渐递减到4 nm,InGaN/GaN多量子阱活性层中In组分保持一致并为15~18%。
(6)在1000~1100 ℃的温度下生长厚度10~20 nm的p-AlGaN电子阻挡层。
(7)在1000~1100℃的温度下生长厚度200~300 nm厚的p-GaN层。
    与现有技术相比,本发明的优点是:减小GaN/p-AlGaN层间的界面极化效应,提高了空穴的注入效率和更好地抑制了电子溢出,有源区的电子空穴浓度均匀性和发光效率都得到改善。不同阱层厚度可以实现发射峰的变化最终实现GaN基芯片的宽蓝光波长发射,与黄光荧光粉封装在一起能有效改善荧光转换白光LED的显色性。
根据显色指数公式:                                                
Figure 497708DEST_PATH_IMAGE002
Figure 414848DEST_PATH_IMAGE004
为1~8号试验色的光谱辐射亮度因数,分别对应淡灰红色、暗灰黄色、饱和黄绿色、中等黄绿色、淡蓝绿色、淡蓝色、淡紫蓝色、淡红紫色等8种颜色)来看:如果保持YAG:Ce荧光的黄光发射光谱不变,适当增加蓝光芯片发射宽度可以提高其蓝紫光和蓝绿光部分的发射强度(如图1所示),同样可以增加白光LED的显色指数。这样只需对目前蓝光芯片的外延结构进行设计实现宽蓝光波长发射芯片,不需改变目前荧光转换的白光LED的其他任何工艺就能实现高显色指数的荧光转换白光LED制备,该方法具有成本低、制作简单的特点。
附图说明
图1 不同半高宽的蓝光芯片发射光谱。
图 2 (a)传统垒层和阱层厚度不变的多量子阱活性层LED与(b)垒层和阱层厚度渐变的多量子阱活性层LED的外延结构示意图。
图 3 垒层和阱层渐变的多量子阱活性层芯片与YAG:Ce黄光荧光粉封装的白光LED的发射光谱图。
具体实施方式
下面结合附图和具体实施例进一步详细说明本发明。除非特别说明,本发明采用的试剂、设备和方法为本技术领域常规市购的试剂、设备和常规使用的方法。
    现有GaN基LED外延片结构的衬底材料可采用蓝宝石、SiC、Si、GaN等。低温缓冲层可采用低温GaN层、低温AlN层等等。在采用GaN为衬底时可以不生长低温缓冲层和未掺杂GaN层。多量子阱结构有InGaN/GaN结构、InGaN/AlGaN结构、InxGa1-xN/InyGa1-yN结构等等。
    本专利中传统垒层和阱层厚度不变的多量子阱活性层LED外延片结构示意图见图2(a)。其结构从下至上依次为衬底、GaN缓冲层、GaN本征层、n-GaN层、6~8个周期的InGaN/GaN多量子阱量子阱、p-AlGaN电子阻挡层和p-GaN层。垒层和阱层厚度渐变的多量子阱活性层LED外延片的结构如图2(b)所示,InGaN/GaN多量子阱活性层的InGaN阱层的厚度从n-GaN到p-GaN方向逐渐增大,而GaN垒层厚度从n-GaN到p-GaN方向逐渐减小。
    其制备方法为:
    1. 采用GaN专用MOCVD,升温至1000℃在氢气氛围下烘烤衬底10分钟;
    2. 降温至480℃,在衬底上生长厚度为30 nm的GaN低温度缓冲层;
    3. 升温至1050℃,生长厚度为2 μm的未掺杂GaN层;
    4. 在1050℃的温度下生长厚度为2 μm的n-GaN:Si层;
    5. 将温度降至700℃分别生长6个周期的In0.16Ga0.84N/GaN量子阱,垒层厚度从n-GaN到p-GaN方向分别为16 nm、14 nm、12 nm、10 nm、8 nm、6 nm、4 nm,而阱层厚度从n-GaN到p-GaN方向分别为2.0 nm、2.2 nm、2.4 nm、2.6 nm、2.8 nm、3.0nm。
    6. 在1050℃的温度下生长厚度为20 nm的p-Al0.15Ga0.85N:Mg层;
    7. 在600℃的温度下生长厚度为200 nm的空穴浓度为5x1017cm-3的p-GaN:Mg层。
    8. 将外延片经过光刻、腐蚀、ICP刻蚀、蒸镀电极、合金、研磨、划片、裂片、测试和分选等标准的芯片制备工艺制备出尺寸为300 μm x 300 μm的芯片。
    阱层和垒层渐变的宽蓝光波长芯片与封装支架固晶、烘烤和焊线等工艺,而YAG:Ce荧光粉和环氧树脂或硅胶混合、搅拌和除气等工艺,然后将YAG:Ce荧光粉和环氧树脂或硅胶混合物点胶到经过固晶焊线后的支架上,并进一步烘烤定型制备出宽蓝光波长芯片激发YAG:Ce荧光粉的白光LED。图3表示宽蓝光波长芯片与YAG:Ce荧光粉封装成白光LED的发射光谱图。其中:宽蓝光波长发射峰是来自阱层和垒层渐变的In0.16Ga0.84N/GaN多量子阱的发射,而570 nm则是来自宽蓝光激发YAG:Ce荧光粉的发射。

Claims (9)

1.一种GaN基宽蓝光波长LED外延片,从衬底开始,依次为GaN缓冲层、GaN本征层、n-GaN层、InGaN/GaN多量子阱层、p-AlGaN层和p-GaN层,所述的InGaN/GaN多量子阱层由InGaN阱层和GaN垒层交替叠加而成,其特征在于,所述的InGaN/GaN多量子阱活性层的InGaN阱层的厚度从n-GaN到p-GaN方向逐渐增大,所述的InGaN/GaN多量子阱活性层的GaN垒层厚度从n-GaN到p-GaN方向逐渐减小。
2.根据权利要求1所述的GaN基宽蓝光波长LED外延片,其特征在于,所述的InGaN/GaN多量子阱层中的量子阱的数量为4~6。
3.根据权利要求1所述的GaN基宽蓝光波长LED外延片,其特征在于,所述的InGaN阱层厚度,从n-GaN到p-GaN方向,由2 nm递增到3 nm,所述的GaN垒层厚度,从n-GaN到p-GaN方向,由16 nm递减到4 nm。
4.根据权利要求3所述的GaN基宽蓝光波长LED外延片,其特征在于,所述的递增为等差递增,所述的递减为等差递减。
5.根据权利要求1所述的GaN基宽蓝光波长LED外延片,其特征在于,InGaN阱层中In的摩尔量为Ga和In的总量的15~18%。
6.根据权利要求1所述的GaN宽蓝光波长LED外延片,其特征在于,所述的p-GaN层掺有受主Mg,所述的n-GaN层掺有施主Si。
7.根据权利要求1所述的GaN基宽蓝光波长LED外延片,其特征在于,所述的衬底为蓝宝石、硅、SiC或GaN中的一种。
8.一种白光LED,其特征在于,由权利要求1所述的GaN基宽蓝光波长芯片与黄光荧光粉结合封装而成。
9.根据权利要求8所述的白光LED,其特征在于,所述的白光LED的发射峰值的范围在550~590nm,所述黄光荧光粉为YAG:Ce+、硅酸盐、铝酸盐或氮化物中的一种。
CN201310466986.7A 2013-10-09 2013-10-09 一种GaN基宽蓝光波长LED外延片及其应用 Pending CN103515497A (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201310466986.7A CN103515497A (zh) 2013-10-09 2013-10-09 一种GaN基宽蓝光波长LED外延片及其应用

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201310466986.7A CN103515497A (zh) 2013-10-09 2013-10-09 一种GaN基宽蓝光波长LED外延片及其应用

Publications (1)

Publication Number Publication Date
CN103515497A true CN103515497A (zh) 2014-01-15

Family

ID=49897896

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201310466986.7A Pending CN103515497A (zh) 2013-10-09 2013-10-09 一种GaN基宽蓝光波长LED外延片及其应用

Country Status (1)

Country Link
CN (1) CN103515497A (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103779462A (zh) * 2014-01-21 2014-05-07 中国科学院半导体研究所 一种提高发光效率的led结构
CN103996768A (zh) * 2014-05-30 2014-08-20 西安神光皓瑞光电科技有限公司 一种用于光电器件的多量子阱结构

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63200586A (ja) * 1987-02-17 1988-08-18 Matsushita Electric Ind Co Ltd 半導体装置
CN101714602A (zh) * 2009-11-18 2010-05-26 上海蓝光科技有限公司 用于光电器件的多量子阱结构

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63200586A (ja) * 1987-02-17 1988-08-18 Matsushita Electric Ind Co Ltd 半導体装置
CN101714602A (zh) * 2009-11-18 2010-05-26 上海蓝光科技有限公司 用于光电器件的多量子阱结构

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
BIN CAO ET.AL: "Enhancing Light Output of GaN-Based LEDs With Graded-Thickness Quantum Wells and Barriers", 《IEEE PHOTONICE TECHNOLOGY LETTERS》, vol. 25, no. 18, 15 September 2013 (2013-09-15), XP011524687, DOI: doi:10.1109/LPT.2013.2275166 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103779462A (zh) * 2014-01-21 2014-05-07 中国科学院半导体研究所 一种提高发光效率的led结构
CN103996768A (zh) * 2014-05-30 2014-08-20 西安神光皓瑞光电科技有限公司 一种用于光电器件的多量子阱结构

Similar Documents

Publication Publication Date Title
CN101208810B (zh) Ⅲ族氮化物白光发光二极管
US8421058B2 (en) Light emitting diode structure having superlattice with reduced electron kinetic energy therein
CN101346827B (zh) Ⅲ族氮化物白光发光二极管
US8178888B2 (en) Semiconductor light emitting devices with high color rendering
US20180351039A1 (en) Light-emitting device and lighting device including the same
US20140225139A1 (en) Light emitting device package and method of manufacturing the same
CN101582418B (zh) 电注入调控三基色单芯片白光发光二极管
US7608994B2 (en) White light emitting device
CN108389941A (zh) 显指可调的无荧光粉单芯片白光led器件及其制备方法
CN102347408B (zh) GaN基双蓝光波长发光器件及其制备方法
JP2001028458A (ja) 発光素子
CN107170866A (zh) 一种多光谱发光二极管结构
US11557695B2 (en) Single chip multi band LED
CN101562222B (zh) 背面出光的单芯片白光发光二极管及其制备方法
CN104218125B (zh) 一种白光led的生长方法及利用该生长方法制备的白光led
CN100411211C (zh) 单片集成白光二极管
CN103515497A (zh) 一种GaN基宽蓝光波长LED外延片及其应用
JP3511923B2 (ja) 発光素子
CN112436085A (zh) 发光二极管灯丝及照明装置
KR20160024533A (ko) 형광체 조성물 및 이를 포함하는 발광 소자 패키지
US20190169496A1 (en) Red phosphor and light emitting device comprising same
JP2002208731A (ja) 半導体発光素子
KR102399381B1 (ko) 발광소자
US20230282768A1 (en) LED Structure and Manufacturing Method thereof, and LED Device
JP2003197969A (ja) GaN系半導体発光素子およびそれを用いた発光装置

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20140115

WD01 Invention patent application deemed withdrawn after publication