Report for China Frontier Workshop(June 22nd 2006 Beijing)

Wang Zhanguo

Key Lab. of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences,

P. O. Box 912, Beijing 100083,P.R.China

Outline 1. A Brief introduction of the IS,CAS

2. Main research projects and achievement in our Lab

4. Topics interesting for international collaboration

1. A Brief introduction of the Institute of Semiconductors, Chinese Academy of Sciences

The Institute originally was a division of the Institute of Physics, CAS, and it was independent on the 16th September 1960.

Through the period of more than 45 years, the Institute has now grown up a multidisciplinary research institution and research areas includes semiconductor physics, materials, devices and their applications.

It has two national research centers, three state key labs, one key lab of CAS , 10 joint venture enterprises, Library and Information Center etc.

Main Research Building

Compound Crystal Technology Co., Ltd can supply LEC,VGF and HB GaAs with 2-6 inches and 2-3 inches InP Epi-ready wafers.

The Integrated Technology Center

There are now 452 staffs in the Institute, 270 are academic staffs including 71 full professors and 62 associate professors. There are seven Members of the CAS and two Members of the CAE.

The institute has 408 postgraduate students, 18 postdoctoral researchers, 233 PhD and 157 MSc students, respectively.

Molecular Beam Epitaxy system for low dimensional semiconductor structures

growth:QDs and QWRs etc.

MOCVD system for GaN based LED and LD structures growth

Molecular Beam Epitaxy system (V80) used for growing magnetic semiconductors

Class 10 clean-room for semiconductor integrated technology

Electron Beam Lithograph system with high resolution of 10nm (left) and The

functional integration Lab of optoelectronic devices (right)

2. The main research projects carried out in my group are as follows:

1.1. Semiconductor nano-structures and quantum devSemiconductor nano-structures and quantum devicesices

2. Positional growth of QDs and QWRs2. Positional growth of QDs and QWRs3.3. GaAs and InP based quantum cascade materials GaAs and InP based quantum cascade materials

and lasersand lasers4.4. Wide band-gap semiconductor thin films and nanWide band-gap semiconductor thin films and nan

ostructures growthostructures growth5.5. Organic/inorganic composite semiconductors for Organic/inorganic composite semiconductors for

solar cells solar cells

Research founding supported by NSFC, 863 Hi-Tech and 973 National Major Basic Research Program etc.

Changing In composition x of InGaAs QDs

x=0.3 x=0.4 x=0.5

Lift 1 and 2 are the 2D AFM images of InxGa1-xAs QDs grown on (311)B GaAs substrates.

3D images of InxGa1-xAs / GaAs (311)B QDs (0.4 0.4m)

Inserting In0.5Al0.15Ga0.35As strain reducing layer between QD layer & substrate

d)

b a

c

(a), (b) and (c), (d) are without and with the buried layer respectively.

Comparing fig.a,b and c,d, the In

0.4Ga0.6As QDs de

nsity is increased and ordering effect is improved largely.

Characteristics of high power In(Ga)As/GaAs QDLD

Light output power from the uncoated facets vs the current

EL spectra of a QD laser below and above the threshold current

The samples of high power QD laser diodes

960nm10W QDLD optical fiber module

Width of LD, 200m

Cavity length 600m

0 1000 2000 3000 4000 5000 60000.0

0.5

1.0

1.5

100m apertureuncoated surface

power from both facets

Po

wer

(W

)

Time (hour)

The schematic structure of inclined stripe quantum-dot SLD

P -m eta l

S iO 2

1 m P -A l G a A s 0 .5 0 .5

m A l G a A s (y= 0 -0 .5 )y 1 -y

Q u an tu m d o ts ac tiv e reg io n

0 .2 m A l G a A s (y= 0 .5 -0 ) y 1 -y

1 m n -A l G a A s 0 .5 0 .5

(1 00 ) n G aA s S u bstra te+

0 .5 m n G aA s b u ffe r +

m p G aA s+

6 O

900 950 1000 1050 1100

Wavelength (nm)

1400mA

EL

Inte

nsi

ty

(a.u

.)

400 600 800 1000 1200 1400

0

50

100

150

200

Lig

ht

Ou

tpu

t (

m W

)

Injection Current (mA)

Light output power of the QD-SLD under CW operation at RT.

Output spectrum of QD-SLD under 1400mA CW pumping current at RT.

The Characteristics of quantum dot-SLD: CW output power 200mW, the spectral bandwidth 60nm at RT

10nm （ 110 ）

（ 1-10 ）

The diagonally aligned self-assembled InAs/InAlAs/InP(100) QWR arrays

The cross-sectional TEM images and PL spectra of 5 periods 6.5 ML InAs / 10 nm InAlAs QWR arrays.

The alignment of the QWRs grown on InP substrates with different buffer layers

InAs/[(InAlAs)2/(InGaAs)2]

InAs/InGaAs/InP QWRs

InAs/[(InAlAs)4/(InGaAs)2]

30nm

a

dc

InAs/InAlAs/InP QWRsb

Symmetry in the InAs wire alignment

MBE, (001), 8ML MEE, (001), 8ML

MBE, (mis-oriented), 8ML MEE, (001), 10ML

Lower Left fig. shows InAs QWRs grown on the (110) cleavage surface of GaAs/AlGaAs SLs

Lower right fig. demonstrates the InAs QDs grown in the patterned GaAs substrates.

)(24.1 23 EE

Particle population inversion based on the resonance with the optical phonon.

meVEE 3512

This SL has double merits: n=3’s Bragg reflector,n=1’s electron extraction.

Operation principle of quantum cascade laser

The lower left fig. shows the TEM result of strain-compensated In0.55Ga0.45As/In0.5Al0.5As

The lower right fig. shows the XRD spectrum of 25 period In0.55Ga0.45As/In0.5Al0.5As QCL

29 30 31 32 33 34 35

100

101

102

103

104

105

106

Inte

nsi

ty (

a.u

.)

Theta

G069

The output power vs current for the 5.5m strain-compensated QCL

0 1 2 3 4 5 6 7

0.0

0.5

1.0

Po

we

r (W

)

Current (A)

1W QCW operation at 80K

4 6 8 10

50C 脉冲激射

800 900 1000 1100 1200 1300 1400

INT

EN

SIT

Y(a

.u.)

FREQUENCY （ cm-1 ）

83K 9.1m GaAs/AlGaAs QCL lasing spectrum

2 4 6 8 10 12 14 16

0

1x103

2x103

3x103

Inte

nsity

(a.u

.)Wave length (m)

7.8m strain-compensated QCL lasing spectrum

Samples for quasi-single mode quantum cascade lasers made by our Lab.

84K83K

15 Min CSI 15 Min CSI

60 Min CSImin 60 Min CSI

ZnO nanostructures grown by Stress drivingFig. （ a ） , （ b ） and （ c ） , （ d ） are FE Cross Section Imaging at growth time of 60min and 15min respectively

3. Topics interesting for international collaboration Positional growth of semiconductor QDs and QWRs

Quantum dot devices for systems applications

such as: high power QD Laser, 1.3mand 1.5m QD

lasers, super- luminescence diodes for optical fiber

communication; QD inferred detectors; QD single

photon source for quantum computation etc.

Band energy engineering design for THz (30-300m)

structures and lasers

Property studies on single QD and QWR

Thanks for your attention！