Transcript Document 7242788

Armenian science potential in
Semiconductor Chemical
Sensors and Solar Cells
made of Nanostructures
and commercialization
proposals
Vladimir AROUTIOUNIAN
ArmTech 2 Congress
October 4, 2008, Panel II Yerevan, Armenia
Yerevan State University
DEPARTMENT
OF PHYSICS OF SEMICONDUCTORS &
MICROELECTRONICS
and
RESEARCH CENTER OF SEMICONDUCTOR DEVICES
AND NANOTECHNOLOGIES
(Faculty of Radiophysics)
40 students per year
2 PhD students per year
Participation in teaching of 12 students per year for
SYNOPSYS-ARMENIA
12 Professors, Docents and Ass.-Professors
24 Researchers
TECHNOLOGIES
• Ceramics
• Thin Films Evaporation (thermal,
plasma assisted, magnetron etc.)
• Liquid- , Electroliquid
& “Step Cooling” Liquid Phase Epitaxy.
• Sol-gel
• Growth of Single Crystal, Multi- and
Nanocrystalline as well as Porous
Semiconductors
• Nanoparticles and Nanograins
SCIENTIFIC ACTIVITY:
Main directions today
• SILICON, INCLUDING NANO&MICROPOROUS SILICON.
• 3-5 SEMICONDUCTORS (InAs, InAsP, InAsP etc.). GRADED BANDGAP
SEMICONDUCTORS.
• SILICON CARBIDE. DIAMOND LIKE CARBON.
• INFRARED, MAGNETO- and UV DETECTORS. INJECTION
PHENOMENA. NOISE
• QUANTUM-SIZE EFFECTS IN SEMICONDUCTORS. NANOSCALE
PHYSICS,TECHNOLOGY AND ELECTRONICS
• THERMOELECTRICITY
• SEMICONDUCTOR INTERFACE with DIFFERENT MEDIA.
• SEMICONDUCTOR METALOXIDES. CHEMICAL SENSORS
• CONVERSION of SOLAR ENERGY into HYDROGEN, HEAT
and ELECTRICITY
METAL OXIDE PHOTOELECTRODES FOR HYDROGEN
PHOTOELECTROCHEMICAL GENERATION
• An increase in the efficiency of conversion of solar
energy into hydrogen is realized by the deviation from
stoichiometry of stable in water electrolytes metal
oxides (TiO2-x etc.) or appropriate doping of n-type
oxides with different impurities. Best results in world
in the efficiency, but not enough for large scale
applications.
• Photoelectrodes made of n-and p-type single
crystalline, thin films and nanotubes.
• Synthesis of new semiconductor phases made of solid
solutions of wide band gap oxide (more than 3 eV) and
rather small band gap oxide (corresponding to the
maximum of the solar radiation spectrum).
Photoelectrolysis setup (one from 4 versions)
Unique in the world
2
6
3
1
Photoelectrolysis setup
with compound parabolic
6 cylindrical concentrator:
1- body of PECell
2 - quartz windows;
5 3 - semiconductor matrix;
4
4 – electrolyte;
5-ion-exchanging membrane;
6-parabolic-cylindrical
concentrator.
-
TiO2 nanotubes
Photoelectrical Conversion
of Solar Energy
Multilayer Antireflection Coatings for Silicon Solar Cells
Nano porous silicon, diamond, silicon oxinitride etc. thin
films –YSU+ P.Soukiassian (Saclay, France). Covered by 2
French Patents
Reflectance, %
Reflectance spectrum of DLC/PS (solid line) and SiO2/TiO2 double
layer ARCs (dash-dotted line)
20
15
10
5
0
400
500
600
700
Wavelength, nm
800
900
CONVERSION OF SOLAR ENERGY TO
ELECTRICITY BY PHOTOVOLTAIC AND
THERMO PHOTOVOLTAIC CELLS
THERMO PHOTOVOLTAIC CELLS (YSU) made of InP-InAs System.
Graded-bandgap photodiodes and position-sensitive detectors made
of 3-5 semiconductors grown in YSU by liquid and electroliquid epitaxy
[V. Aroutiounian, K. Gambaryan, V. Gevorgyan (now in Russ-Slavonic
Univ. Yerevan)].•
• Quantum dot nanocrystalline solar cells [ Aroutiounian, A. Khachatryan,
S. Petrosyan (now in Russ-Slavonic Univ. Yerevan), and K. Touryan
(USA); A. Kechiyants (Inst. For Radio Phys. & Electronics, NAN,
Ashtarak)] and other nanoscale photodevices
QD cells proposed in YSU in 2000 and realized in Japan in 2003.
• Now we have first experimental samples with QDs grown un YSU (K.
Gambaryan). We realized SELF–ASSEMBLED InAsSbP - BASED
STRAIN INDUCED ISLANDS ON InAs SUBSTRATES AND SAW THEIR
EVOLUTION FROM PYRAMIDS TO QUANTUM DOTS
• “SOLAREN” (V. Afiyan) and “TRANSISTOR” (A. Vardanyan) produced in
small scale solar panels using silicon solar cells made out of Armenia. STUA
are working on covering of Si solar cells with diamond like carbon ARC (J.
Panosyan)
•
Investigation of Optical and Photoelectric
Properties of Semiconductor-Liquid
Crystal Interface
• Improve the Time Characteristics of the
Semiconductor-Liquid Crystal System
• Based Electrooptical Devices by using Interface
Controlled Effect
• Increasing of Giant Optical Nonlinearity (GON)
by using semiconductors as a substrate in
Liquid Crystal cells
• Manufacture of new type of devices based on
this effect (H. Margaryan)
CHEMICAL SENSORS and GAS DETECTORS
• Besides residential applications, gas and fire
detectors are used under operating conditions at
fossil as well as nuclear power plants, in fuel cells
in order to prevent different type incidents. It is
necessary to have аn information about the
concentration of hydrogen, methane, carbon
monoxide and dioxide as well as other gases and
humidity in order to prevent false alarm.
• Research and development of world class
semiconductor metal-oxide adsorptive sensing
elements (with micro-and nano size of sensitive
grains) for different gases made of different
metaloxide semiconductors as well as integral
components of new type sensors and detectors or
non-expensive
Hybrid Multisensor Security
System for the market are carrying out in YSU
Hydrogen and CO Sensors
• Development and investigation of corresponding technologies
and regimes for obtaining of relatively thermally stable nanosized SnO2 particles of very small dimensions and thin films
on its base.
• The sensitivity of gas sensors strongly depends on
nanocrystallites’ smallness. Weak dependence of grains size
on films calcinations temperature found.
• Low operating temperatures and consumed electric power are
typical for our sensors.
• The sizes of nanoparticles measured using TEM shows that
offered by us technique ensures more stability of grain sizes
(in comparison with known techniques). The SnO2 grains
remained less than 6 nm even after the calcinations at 750oC.
• Hydrogen sensors were manufactured both for multisensor enose array and fuel cell hydrogen leak warning.
• We are planning to develop new sensors for different gases
and use Synopsys tools to design of corresponding cheap enose for home and office defence.
• Different materials such as semiconducting oxides
(Sn02, ZnO, TiO2, Fe203), catalytic oxides (V2O5,
MoO3, CuO, NiO), metals deposited on oxide supports
(Pt/Sn02, Pt/ZnO, Pd/SnO2), and mixed (or complex)
oxides exhibit different physical properties on
exposure to different gas species.
• Even though the semiconductor oxides used for gas
sensors are catalytically active, a small amount of a
catalytic metal or metal oxide is often added to
improve their selectivity and sensitivity.
• Main investigators in YSU in the field of metal oxide
semiconductors are now Z. Adamyan, V. Arakelyan,
Kh. Martirosyan, G. Shahnazaryan, A. Adamyan, Z.
Mkhitaryan, V. Galstyan, G. Stepanyan, E.
Khachaturyan, H. Asriyan etc.
• First 4 scientists and V. Aroutiounian got the
Prize of President of Armenia for investigations
in 2004-2006.
The sensor sample packed in TO-5 case
Teflon carrier
The contacts with
golden wire
thermocompression
bonding
H2 sensitivity vs. operating temperature
Sensitivity, R air /Rgas
100000
10000
1000
5000ppm
100
1000ppm
10
0
100
200
300
o
Temperature, C
400
Another type hydrogen gas sensor working without
pre-heating of work-body is proposed in collaboration
with Prof. P. Soukiassian and shown in Figure. Pt
catalytic layer and Au electrical contacts were
deposited by ion-beam sputtering on metal oxide thin
film which prevent porous silicon sensitive layer from
oxidation. All types of sensors are covered by patents.
Noise spectroscopy of gas sensing
1E-8
air
1E-9
2
Su(f)/U , Hz
-1
1E-10
air+0.4% CO
1E-11
1E-12
1E-13
air+1.7% CO
f, (Hz)
1E-14
1
10
100
Fire & Smoke Detectors
Fire detection and registration at the early stages
has always been an extremely important problem. It
is concerned with, primarily, guarantees of safety of
human life and health, pre-serving buildings and
constructions as well as environment ecology.
New, absorption type smoke detectors with cheap
semiconductor sensitive chip are developed by us.
Detectors are covered by several patents including
the US one.
Recently we successfully partly tested our detectors
in Southwest Research Institute (San Antonio, USA).
Regretfully, we had not the amount for full testing.
Our detectors’ cost and size are much lower than
they for photoelectrical and radioactive ionization
detectors, which are today in the market.
Most relevant applications of the Products
Bi2O3 adsorptive type smoke and NOx sensors
(Patented in Armenia, the first modification was Patented in US)
The Product is most effective at fire detection in early stages of smoldering and can be
extremely useful in multi-sensor solutions in Home security systems and e - noses
Other applications
•Dwelling houses and apartments, hotels, hospitals.
• Specialized installations:
a. Military and civil warehouses, depot, aircrafts hangars, plant facilities.
b. Elevator (wells) and communication lines shafts of high-rise buildings, underground
communication lines, subway systems.
•Aircrafts and ships
•Ecologic monitoring of environment *)
*) The product is applicable for environmental monitoring in large cities, where the motor
transport concentration is high, and in industrial cities for air monitoring with the object to
monitor the norm excess content of SOx and NOx gases.
It can provide ecological monitoring of environment in system of “electron nose” on high
altitudes in mountainous regions and in intensive areas of pass of Wind Rose.
It can also work without fail at autonomously energy supply to function in sensor net
system for early fire warning in large forest tracts.
Such companies as Invensys Sensor Systems and NOTIFIER - Fire Alarm
Systems and Technology were considered by IC2 Institute technology assessing
teams as potential partners for future commercialization of the product.
Most relevant applications of the Products
Nanocrystalline SnO2 thin-films based sensors for Hydrogen and CO detection
(Patented in Armenia); the product is developed under DOE funding.
Porous silicon – metal oxide tandem nanostructures for Hydrogen and other hazardous
gases sensing including CO (Patented in Armenia)
Hydrocarbon Gas and Methane Nanosensors made of ZnO and other metal oxides (Know how)
The key advantage of such low cost nanosensors are high sensitivity and workability of the sensing element nearby room
temperatures, possibilities to realize multi-sensor solution made on single crystal chipset platform.
Applications:
Hydrogen propelled/integrated critical infrastructure and autonomous systems monitoring
• Home security systems, E-noses
• Fuel cells
• Security multi-sensor solutions
• Environment monitoring systems
• Gas pipelines monitoring systems
The key advantage of the Product is able to detect Hydrogen and various Hazardous gases with controlled
sensitivity
In our opinion Honeywell International Inc. can foster patentable potential in this product upgrade.
Local market is considered as the most effective investment zone for large-scale production of such
nanosensors.
•The non-military world market for sensors exceeded expectations
with US $ 32.5 billion in 1998.
Up to 2003, this market growed at an annual rate of 5.3% reaching
up to US $ 42.2 billion.
•In 2008 the global sensor market volume could even reach US $
54 billion.
•The world sensors market is expected to reach US $ 61.4 billion
by 2010.
Sensor types with the highest demand volumes worldwide are
temperature sensors, pressure sensors, flow sensors, binary position
sensors (proximity switches, light barriers, reflectortype photosensors),
position sensors, chemical sensors for measurement in liquids and
gases, filling sensors, speed and rpm-sensors, flue gas sensors and fire
detectors.
The fastest growing types of sensors include rain sensors, thickness
sensors, sensors that measure the quality of liquids, navigation sensors,
tilt sensors, photodetectors, glass breakage sensors, biosensors,
magnetic field sensors, and motion detectors.
World Market for Sensors
World Market for Sensors
Human resourses
Yerevan State University
40 students are graduated annually in the fields of
Radio physics, Microelectronics and Semiconductor
Physics. Research Center of Semiconductor Devices
and Nanotechnologies is working now.
State Engineering University of Armenia
40 students are graduated annually in the fields of
Radio electronics and Circuitry Russian-Slavonic
University
20 students are graduated annually in the field of
Semiconductor electronics
• All mentioned above materials, photoelectrodes,
cells, sensors and setups were made in our
Department in YSU. Several modern technological
equipment and measurement setups were
purchased in the framework of our International
grants.
• We have about 40 Patents (including the USA,
France, Russian Federation, USSR and Armenia
ones) and are authors of several hundreds
publications in West countries and USSR’ journals
as well as in Proceedings of International
Conferences and Meetings.
• Several conferences were organized by us in
Armenia.
• About 100 citations of our papers were made by
foreign scientists in leading journals only in 4 last
years.
Now we are waiting for new names of
peoples and companies who can help
us
to
correctly
organize
the
commercialization and production
(preferable in Armenia) of proposed
and realized by us samples of new
type smoke and gas detectors,
photoelectrolysis cells and thermo
photovoltaic devices as well as
antireflection coatings for silicon solar
cells and to help us in the realization
of our promising nanoscale devices!!!