Transcript a) Sensors for Biomedical Applications b) Electroluminescence of FeSi in Si

Photonics Activities within Solid State Lab
a) Sensors for Biomedical Applications
b) Electroluminescence of FeSi2 in Si
c) Polymer Light Emitting Diodes
Department of Electronic Engineering
The Chinese University of Hong Kong
Academic units & industrial partners in support of
photonic sensor R&D in CUHK
EE – optoelectronics, guidedwave devices, biomedical
electronics, signal processing,
device fabrication
ACAE – Centre for Micro
and Nano Systems, MEMS,
micro-fluidics, device
modeling
Industrial
Partners
Photonic
Sensor
R&D
Biochemistry and Medicine –
application area identification,
supporting facilities, biomolecule
selection, bio-material supply,
field trials
Physics – laser optics,
optical diagnostic facilities,
novel materials
E-Care Company Ltd. (wireless healthcare devices)
Automatic Mfg. Ltd. (high volume device manufacturing)
Photonics Instruments (equipment R&D)
Hong Kong Healthcare Services Ltd. (sales and marketing)
Hong Kong Health Digit Co. Ltd. (diagnostic equipment)
Chan & Hau Medical Laboratories (medical services)
Micro-Photonic Sensors for Biomedical
Applications
CUHK’s photonics technologies and techniques
Surface Plasmon Resonance, Integrated Optics (Prof. Aaron Ho, EE)
Optical Fibre Phosphorescence (Prof. Dennis Lo, Phys)
Biomolecules to be detected
Application Examples:
Antigen/antibody
Health care diagnostics
Environmental monitoring
Food and drink industries
Drug R&D
Agriculture
Oxygen
Toxins
Carcinogens
body fluids/blood/urine
Virus, cells, bacteria
DNA, genomic fingerprints
Pollutants
Food ingredients
Surface Plasmon Resonance Biosensors
ksp
Metal
Surface
Plasmon
Wave
q
Lowest
Reflectivity
Differential
Phase SPR
Sensor
Biomolecule detection response curve
differential phase (degrees)
200
150
Non-BSA Antibody
Into flow cell
=>No binding
BSA Antibody into flow cell
=>specific binding
110ug/ml
100
37ug/ml
50
PBS
PBS
3.7ug/ml
0
-50
0
50 100 150 200 250 300 350 400 450
time (sec.)
Reaction curve of BSA (bovine serum albumin) with non-BSA
antibody with different concentrations of BSA antibody
Relative phase change (degree)
Sensitivity limit of our SPR system
Phase change caused by varying concentration of
glycerin/water mixture (Au surface)
160
140
120
100
80
60
40
20
0
0
60
40
20
Time (min)
0
0
50
100
150
200
250
-20
-40
2
4
6
Concentration of glycerin (%)
glycerin
(%)
refractive
index
Relative
phase
change
(°)
0
1.3330
0
0.25
1.3333
21.75
0.5
1.3336
32.59
1
1.3342
57.53
2
1.3353
89.32
4
1.3400
112.59
8
1.3424
135.69
8
10
-60
Sensitivity limit of our system:
Au surface: 1.38 x 10-7 RIU (Refractive Index Unit)
Au/Ag surface: 5.48 x 10-8 RIU
Sensitivity Comparison Between Systems
Sensing
Principle
BIAcore
IBIS
3000 (prism- (vibrating
based SPR) mirror
SPR)
Plasmoon
(broadrange SPR)
SPREETA
(prismbased SPR)
IASys
(resonant
mirror)
Refractive
index range
1.33-1.40
1.33-1.43
1.33-1.48
1.33-1.40
-
Limit of
detection
(RIU)
*3 × 10-7
2 × 10-6
6 × 10-6
3 × 10-7
>1 × 10-6
Sensitivity limit of our system:
Au surface: 1.38 x 10-7 RIU (Refractive Index Unit)
Au/Ag surface: 5.48 x 10-8 RIU
Structural and optical properties of FeSi2 nano-crystal
embedded in Si synthesized by MEVVA implantation
PL spectra measured at 80K for
two samples with different
strain states.
SiO
ITO + 2
+
20000
( w)
PL Intensity m
A simple structure of LED device
containing FeSi2 nano-crystal
High strain
low strain
Al
2 nm
0.5μm
2μm
15000
p+ Si
FeSi2
10000
FZ n-Si
5000
bias+
0
0.7
0.8
0.9
1.0
1.1
Photo energy (eV)
1.2
Application of Low Level Birefringence Detection
System for Stress Measurement in Semiconductor
Materials and Structures
Photoelasticity (PE) method for stress analysis
By measuring the change in the state of
polarization of light after passing through the
sample, information on the stresses in the sample
can be obtained
Low Level Birefringence Detection (LLBD) system
A high sensitive PE technique by using Photoelastic
Modulation technique. The sensitivity of current
LLBD system is: 0.02º
Application of Low Level Birefringence Detection
System for Stress Measurement in Semiconductor
Materials and Structures
tS iO2= 1.3 mm
tSi = 380 mm
SiO2
0
Si
Unit:  107 dyne/cm2
x
y
85
Retardation (Degree)
80
75
70
65
(11 0)
60
55
Distribution of residual stress in the 2- inch bare (100)
GaAs wafer
50
45
-2000
-1000
0
1000
2000
x (minduced
m)
Plot of distribution of stress
birefringence in
silicon substrate under SiO2 film edge
OLED project team members
Project Director: Prof. K. Y. Wong
Prof. H. F. Chow
Prof. S. K. Hark
Prof. W. M. Lau
Prof. H. C. Ong
Dr. K. W. Wong
Prof. S. P. Wong
Prof. J. B. Xu
Dept. of Physics
Dept. of Chemistry
Dept. of Physics
Dept. of Physics
Dept. of Physics
Dept. of Physics
Dept. of Electronic Engineering
Dept. of Electronic Engineering
CUHK’s areas of interest in PLED

Comprehensive in-house material characterization
facilities (Physics and EE Depts.) to conduct research
on:
a) Interface characterization and engineering
b) Degradation mechanisms and improvement

Development of new materials (Chemistry Dept.)

Device fabrication and technology transfer through
collaboration with industry (Varitronix) and other local
institutions (HKUST, HKBU)

ITF project in collaboration with Varitronix Ltd. (HK $
4M)
Existing facility for PLED
preparation and characterization
XPS, Auger, STM/AFM, SEM, TEM/EELS
PLEDs fabricated
“Green” PLED cell based
on PFO co-polymer from
DOW Chemicals
“Blue” PLED cell based
on PFO from
Prof. H. F. Chow
END