a) Sensors for Biomedical Applicationsb) Electroluminescence of FeSi2 in Si

c) Polymer Light Emitting Diodes

Department of Electronic Engineering

The Chinese University of Hong Kong

Photonics Activities within Solid State Lab

EE – optoelectronics, guided-wave devices, biomedical electronics, signal processing, device fabrication

Photonic

Sensor

R&D

Biochemistry and Medicine – application area identification, supporting facilities, biomolecule selection, bio-material supply, field trials

ACAE – Centre for Micro and Nano Systems, MEMS, micro-fluidics, device modeling

Physics – laser optics, optical diagnostic facilities, novel materials

Academic units & industrial partners in support of photonic sensor R&D in CUHK

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)

Industrial Partners

Micro-Photonic Sensors for Biomedical Applications

Micro-Photonic Sensors for Biomedical Applications

Biomolecules to be detected

CUHK’s photonics technologies and techniques

Surface Plasmon Resonance, Integrated Optics (Prof. Aaron Ho, EE)

Optical Fibre Phosphorescence (Prof. Dennis Lo, Phys)

DNA, genomic fingerprints

body fluids/blood/urineVirus, cells,

bacteria

Toxins

Carcinogens

Oxygen

Antigen/antibody

Food ingredients

Pollutants

Application Examples: Health care diagnostics

Environmental monitoring

Food and drink industries

Drug R&D

Agriculture

Surface Plasmon Resonance Biosensors

Metal

kspSurfacePlasmon Wave

LowestReflectivity

Differential Phase SPR

Sensor

Biomolecule detection response curve

Reaction curve of BSA (bovine serum albumin) with non-BSA antibody with different concentrations of BSA antibody

-50 0 50 100 150 200 250 300 350 400 450

0

50

100

150

200

3.7ug/ml

37ug/ml

110ug/ml

BSA Antibody into flow cell =>specific binding

PBS

Non-BSA AntibodyInto flow cell

=>No binding

PBS

diff

eren

tial p

hase

(de

gree

s)

time (sec.)

Sensitivity limit of our SPR system

Phase change caused by varying concentration of glycerin/water mixture (Au surface)

020406080

100120140160

0 2 4 6 8 10Concentration of glycerin (%)

Rela

tive p

hase

ch

an

ge (

deg

ree)

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

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

-60

-40

-20

0

20

40

60

0 50 100 150 200 250

Time (min)

Sensitivity Comparison Between Systems

Sensing Principle

BIAcore 3000 (prism-based SPR)

IBIS (vibrating mirror SPR)

Plasmoon (broad-range SPR)

SPREETA (prism-based 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

0.7 0.8 0.9 1.0 1.1 1.20

5000

10000

15000

20000

PL

Inte

nsity

( w)

Photo energy (eV)

High strain low strain

PL spectra measured at 80K for two samples with different strain states.

Structural and optical properties of FeSi2 nano-crystal embedded in Si synthesized by MEVVA implantation

A simple structure of LED device containing FeSi2 nano-crystal

2μm

FZ n-Si

0.5μm2 nm

+ +-

bias+

FeSi2p+ Si

SiO2ITO

Al

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

Distribution of residual stress in the 2- inch bare (100) GaAs wafer

(11 0)

Unit: 107 dyne/cm2

tS iO2= 1.3 m

tSi = 380 mSiO2

Six

y

0

Plot of distribution of stress induced birefringence in silicon substrate under SiO2 film edge

-2000 -1000 0 1000 2000

45

50

55

60

65

70

75

80

85

x (m)

Ret

arda

tion

(D

egre

e)

OLED project team members

Prof. H. F. Chow Dept. of ChemistryProf. S. K. Hark Dept. of PhysicsProf. W. M. Lau Dept. of PhysicsProf. H. C. Ong Dept. of PhysicsDr. K. W. Wong Dept. of PhysicsProf. S. P. Wong Dept. of Electronic EngineeringProf. J. B. Xu Dept. of Electronic Engineering

Project Director: Prof. K. Y. Wong Dept. of Physics

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 basedon PFO co-polymer from

DOW Chemicals

“Blue” PLED cell basedon PFO from

Prof. H. F. Chow

END