This document is a description of my activity at the university of
The Algarve. It was written for the application of Associate
Professor in 2011 and includes a CV and the description of
scientific and pedagogic work done. The document is written in the
HTML format to facilitate the modern techniques of browsing through
the document in an electronic fashion and is available online at http://www.stallinga.org/AcadActiv/
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Peter Stallinga, Faro, November 2017
2. Curriculum Vitae
Name: Peter Stallinga Institutional address:
Universidade do Algarve, FCT-DEEI, Campus de Gambelas,
8005-139 Faro, Portugal Tel: +351-289863764 FAX: N/A e-mail:
Social networks: Skype:
Peter Stallinga Twitter:
P. Stallinga ORCID:
Main scientific area of research:
Physics of electronic materials
Other scientific areas of interest: Informatics,
Academic degrees: Agregação
in Physics, University of Porto, 2012. PhD in
Physics, University of Amsterdam, 1994, thesis title
“Investigation of selected paramagnetic centers in semiconductors”
drs in (informatics within) Physics, University
of Amsterdam, 1988
Professor Associado com Agregação, Universidade
do Algarve, Portugal, Faculty of Sciences and Technology, Department
of Electronic Engineering and Informatics, 2012-
Previous positions: Professor
Associado, Universidade do Algarve, Portugal, 2012-2012 Professor Auxiliar with definitive assignment,
2005-2012 Professor Auxiliar,
University of The Algarve, Portugal, 2000-2005 Professor
Auxiliar Convidado, University of The Algarve, Portugal,
University of The Algarve, Portugal, 1997-1999 Current subject,
Electrical characterization of Organic semiconductors.
PostDoc, University of Aarhus, Denmark, 1995-1997
Magnetic resonance of hydrogen-related centers in silicon
PostDoc, University of California at Berkeley,
USA, 1994-1995 Magnetic Resonance and optical characterization of
defects in III-V semiconductors
German (speaking, writing)
Polish (basic level)
Most scientific work was carried out at the University of
The Algarve (UAlg) in the laboratory of OptoEl (later
embedded into the Center for Electronics Opto-Electronics
and Telecommunications, CEOT).
I am at the moment 100% dedicated to CEOT, although many
cooperations exists with other research groups in UAlg,
Portugal (Lisboa) and Europe.
The research up to April 2010 can be divided into the following
branches (in chronological order)
Defects in Semiconductors (Magnetic Resonance)
The Climate (hobby)
This was preformed in European research networks, such as SELOA and
MONA-LISA and national projects with partners in Portugal. In total
cooperations exist(ed) with Amsterdam (UvA), Bologna (CNR),
Eindhoven (Univ. and Philips Research), Durham (Univ.), Marburg
(Univ.), Thiais (Univ.), Wuppertal (Univ.), Pau (Univ.), Glasgow
(Univ.), Würzburg (Univ.), Madrid (IMM), Bergen/Mons-Hainaut
(Univ.), Cambridge (Univ.), Linköping (Univ.), Łódz (Univ.), Banska
Bystrica (Univ.), Lisboa and Aveiro (Univ.), and UFABC (Brasil).
Defects in Semiconductors
Defects, intentionally or unintentionally introduced into the
materials determine the electrical characteristics of
semiconductors. The study and aquired knowledge of these defects has
paved the way for the semiconductor technology to keep following
Moore's law, with ever higher density of transistors and ever
increasing speed of integrated circuits. As a PhD student in
Amsterdam, I used Electron Paramagnetic Resonance (EPR) and related
resonance techniques (ENDOR, FSE, etc) to study these defects in
various semiconductor materials. The main topic was hydrogen in
silicon, where the hydrogen was implanted by a 5 MeV particle
accelerator into bulk silicon. As a highlight, the obtruse hydrogen
molecule was for the first time detected in silicon (Phys. Rev.
In two consecutive PostDoc positions, one in Berkeley (California)
and one in Århus (Denmark), the work was continued. In Berkeley
other materials and techniques were used, including
Photo-luminescence (PL) and Magnetic Circular Dichroism (MCD). The
long-stranding debate as to the origin of the Arsenic antisite in
GaAs was solved (Phys. Rev. B
In Århus I returned to the topic of hydrogen in silicon. This time
not only with EPR but also FTIR (Fourrier-Transform InfraRed
spectroscopy). Many new defects were discovered, some of them for
years in vain tried to find by other groups in the world (Phys. Rev.
Rev. B 2002).
For the electronic components of ultrafast modern computers, defects
are no longer the limiting factor. Moreover, I realized that the
reason for studying radiation defects mainly lies its military
aspects. As such he was looking for a new, more society relevant
research topic and switched his research area in a dramatic way to
Electrical Measurements of Organic Materials at the University of
the Algarve, a young and energetic university with high potential in
The idea in the organic electronics part of the research is
characterizing new organic materials for modern electronics. Such
"plastic electronics" should, in principle, find applications in
low-cost areas such as electronic bar codes. However, plastics, as
we all know, have properties that can be tailor made and thus also
create their own market, in, for example, flexible electronics or
displays. As an example is the major advance in printed electronics
using standard printing techniques such as offset printing, etc.
This kind of electronic devices can only be made with organic
The applications of plastic electronics can thus be subdivided into
light-emitting devices and current-control devices. The example for
the first is LEDs (light-emitting diodes), while for the latter an
FET (field-effect transistor) is the classical example. The research
effort is more or less divided equally over these two areas. The
OptoEl laboratory, in which I am working, is involved in both areas.
The first years were spent on two-terminal devices (Schottky diodes
and pn bipolar diodes) for optical applications using impedance
spectroscopy. As a highlight, a system was built that could measure
deep levels in organic devices. This variant of DLTS (deep-level
transient spectroscopy) was at that time the first successful DLTS
experiment in organic materials, whereas DLTS is a standard
characterization technique for in-organic materials such as Si,
AlGaAs and InP, see J. Appl.
In the latter years research was focused on three-terminal
devices, namely thin-film FETs. Over the years it has become clear
that organic materials in FETs behave similar to amorphous
silicon. In particular, most organic materials cannot be grown
easily in mono-crystalline form and they consequently are
trap-ridden. This causes an efficient trapping of mobile charges
onto deep levels from whence they are difficult to be removed.
Side effects of these traps are 1) Non-exponentially decaying
currents with times scales milliseconds to days. 2) Gate-bias
dependent effective charge mobility. 3) Drain-bias dependent
effective mobility. 4) Stressing (continuous increase of the
threshold voltage on time in operation) 5) Thermally activated
currents 6) Meyer-Neldel rule observation (activation energy of
current depends on bias conditions). This has been summarized in
publications in J. Appl.
Phys (2004) and Org.
Electr. (2006). Moreover, non-linear effects are often
attributed to the contacts. While we have shown this to be
incorrect (non-linear effects are a result of the Poole-Frenkel
type of conduction), it left room for a correct description of the
contacts, which are best described by metal-metal junctions, see Org.
visit to the research group of Dr. Michele Muccini, a
light-emitting field-effect transistor (LE-FET) was
fabricated and measured. This merits to be highlighted
because it was, to our knowledge, the first such device in
the world (Synth.
Recently, a cooperation was started with the University of
Hong Kong for developing electronic devices based on DNA.
In this approach, DNA is treated as any other organic
material, with the advantage of the capability of DNA to
self assemble and self organize. This will enable to
bridge the gap to molecular electronics.
A metal transistor was predicted by me as a direct result of
the way the thin-film transistor was modeled. Because the
device with a metal for the active layer fully behaved as a
transistor, with the source-drain current programmed by the
gate-bias the device worked as a proof-of-principle for the
Algarve Model for transistors.
The metal transistor was considered innovation of the year
in Asia in 2008. See for instance the Research
Highlight in Nature Asia Materials, 6 August 2008. And
received at lot of attention of the media (TV, radio, paper
media, etc.). As an unexpected side effect, in cooperation
with electronics colleagues (Prof. Bastos), the transistor
is found to be possibly much faster than state-of-the art
silicon transistors of equal dimensions. The potential
implications of this are of course enormous.
Building on the knowledge of electrical measurements described
above two projects were started in the OptoEl lab. Measuring living biological entities
using impedance spectroscopy (Bio-FET) in a cooperation with Prof.
Leonor Cancela of the Center of Marine Sciences (Centro de Ciências do Mar). The initial plan was to use FETs as sensing
devices to measure the activity of living cells. Later it was
discovered that using impedance spectroscopy in a micro-electrode
array, the monitoring is much more effective. The interaction of
antibodies of sea shells with parasites was measured in the
evolution of loss-tangent (1/ωRC)(IEEE Sensors 2004). In a
contemporary project, FETs, based on the organic material
sexithiophene (T6) were used in sensing the vapor of TNT commonly
found in land mines. This research was driven by the need for a
cheap and reliable (especially avoiding so-called "false
negatives") sensors to remove the hundreds of millions of land
mines still scattered over our planet, leftovers from less
peaceful times. The use of FETs for the sensing is justified by
their property of being multi-parametric. While simple resistors
could, in principle, also respond to the TNT molecules, their
response is less selective, since the only thing that can change
is the resistance value. FETs have more parameters, such as
mobility, threshold voltage and leakage current. Monitoring all
parameters simultaneously increases the selectivity to, for
instance, distinguish between exposure to oxygen and TNT(IEEE Sensors 2004).
In 2011 a start-up company Vinyar, was created that tries to
address the problem of wine-production failure due to airborne
fungi. The idea is to develop sensing systems to detect and
eliminate the main agent causing the failure of wine.
Instrumentation Optoel being a new laboratory, everything had to be set up
nearly from scratch Moreover, my background was not in the
electrical measurements area but magnetic resonance instead. As a
postdoc in the period 1997-1999 I learned the electrical measurement
techniques, specifically impedance measurements.
Over the years, a variety of measurement systems has been developed
by me, thus turning OptoEl into an instrumentation experts group.
These measurements systems include
- RCL (resistance, capacitance, inductance) Impedance measurements
in the range 50 Hz - 1 MHz based on Fluke PM6306 RCL Bridge.
Measuring: Spectra, RCV Curves and Transients.
- LF-RCL (low frequency RCL) Low frequency impedance measurements in
the range of 1 mHz - 100 kHz home designed, based on a Stanford
Research Systems Lock-In Detector SR830.
- FET (field effect transistor) measurement system, home built,
based on a Keithley 487 picoammeter and a Hewlett Packard 6614C
equipment, measuring IV curves, transfer curves and transients.
- TSC/TSCAP (temperature scanned current/capacitance) for
determining traps and current processes in electronic materials.
- DLTS (deep-level transient-spectroscopy) system dedicated to low
- Quartz Crystal Microbalance (QCM). Measuring resonance frequency
with a Pendulum 666 frequency counter
- Measuring the full impedance spectrum with an HP 8712CNetwork Analyzer.
The latter two were used in a cooperation with the CBME (Centro de Biomedicina Molecular e
Estrutural) research center to measure the kinetics of
chemical reactions, in particular as detectors for DNA and
and Bioelectr. (2007), J. Molec. Recognit.
(2009)). My PhD student, João Encarnação graduated in 2008 in
this field. Thesis title "Development of
Biosensors for Molecular Analysis".
Moreover, I have a background in informatics (studied Experimental
Physics with Informatics branch in Amsterdam) and gained knowledge
in "interfacing" (connecting equipment to computers for control and
data acquisition). Especially the combination of knowledge in
Informatics and one of the Natural Sciences is not often
encountered. For this reason, I was often invited to help set up the
technical equipment in other laboratories. As an example, often
visits were made to the group of Prof. Jorge Morgado in Lisboa to
help with their set-up, or the program Hyper Cromo to measure
impedance spectra transients custom made for the research group of
Prof. Guilherme Ferreira at CBME-Faro. More elaborate projects were
undertaken with the group of Dr. Michele Muccini in CNR Bologna.
Custom-made applications were developed in LabVIEW, Visual Studio
For some time our society is pestered by a pessimistic
outlook for the climate. How can that be? Not twenty years
ago there was no such thing as Global Warming. 30 years ago
the idea was Global Cooling. Moreover, how can it be that
one of the most harmless substances on earth, carbon
dioxide, is attributed the role of responsible agent?
Passionate for the weather and climate since early
childhood, I have been studying both sides of the debate and
can only conclude that Global Warming is the result of the
political way the subject is treated. With international
political bodies such as the IPCC dictating the science, the
outcome of 'research' is inevitable. The ideas were
summarized in a book "De
Mythe Van Klimaatsveranderingen" (Lulu 2010, in
Dutch). This will hopefully reopen the discussion in the
scientifically unhealthy area where saying anything against
the models of Global Warming is considered a crime against
The publication of the book was basis for an interview with
Dagblad, 2010. See short on-line version here.
As well as several seminars were given, see presentations list below.
Several papers were submitted to peer-review journals. Some
have been accepted with the utmost difficulty. It is my
experience that referees use gut-feeling for rejecting the
manuscripts. Still, the truth will prevail. See the special
page about the climate maintained by me: http://www.stallinga.org/Climate/index.html.
It is not possible to base a career on
scientifically analyzing the climate.
Economy. Europe is
in crisis. Why? What is the problem? We have infrastructures
to produce things, yet people are getting poorer. What is
going on here? The problem is in our monetary system. A
system that was invented to avoid a crisis of overproduction
(as predicted by Karl Marx) and now seems to be running
itself into trouble. http://www.stallinga.org/Economy/index.html
Biology. Overlapping with
instrumentation, the idea is to electrically measure living
things. Starting with plants. Currently we are measuring
plant impedance spectroscopy.
Cooperations / Networks
A cooperation was established
with the research center CBME (Centro de Biomedicina Molecular e Estrutural)
of the University of the Algarve, specifically with Prof.
Guilherme Ferreira and Eng. João Encarnação. In this
cooperation, a system was set up to measure the resonant
frequency of quartz crystals with an immediate application
the study of the kinetics of chemical reactions and sensors
for DNA. A talk was given in the CEOT research center about
the progress in February of 2005 (). I
regularly participated in the meetings of the CBME research
Two one-month visits were
made to the Istituto di
Spettroscopia Molecolare, Consiglio Nazionale delle Ricerche in Bologna,
Italy, in the group of Dr. Michele Muccini: July 2002 : In-situ measurements were
carried out of field-effect transistors of BDT and
tetracene. July 2003 : A measurement system
("BolognaFET") was set up for field effect transistors. FETs
of terrylene and tetracene were measured. A light-emitting
field-effect-transistor, LE-FET (the first in the world) was
fabricated and characterized. A system ("PulseFET") was set
up for measuring FETs with ultra-short pulses (20 ns) which
is based on a ultra-fast, high band width, oscillosope of
LeCroy and a pulse generator of Agilent.
A cooperation was started with the Hong Kong University on
the measurement of electronic devices based on DNA
materials. This is still in very early stages. The first
results are on a field-effect transistor. The person
directly involved is Dr. V.A.L. Roy at The Department of
Chemistry of The University of Hong Kong.
Another cooperation with them is the fabrication of the
metal transistor. (Advanced
20, 2120 (2008)).
De Universiteit van
Amsterdam. During a sabbatical leave the Space Separated
Quantum Cutting was discovered and worked out. This resulted
in a publication in Nature Photonics. (Nature
2, 105 (2008)).
to the relevance for society (any increase in energetic
efficiency means decrease in CO2 emissions), this paper
received a lot of national and international attention.
See for instance
Diário de Notícias 23 February 2008, page
Correio de Manhã 2 February 2008, on-line.
NRC (Dutch), paper version,
Release (by P.S.)
Connections have been established with Prof.
Adriano Benvenho of the Federal University of ABC, where
research is done on electronic materials and devices
I started with a teaching load of 12 hours per week in the first
year. This is quite heavy, especially for someone that has to learn
the language and the topic. On average, an hour of theoretical
classes takes about 3 hours more in preparation and an hour of
practical classes about 1 hour more. Responsibility for a
discipline, especially those with a large number of students
consumes a lot of time too. This, of course, all depends on the
quality of the lectures. In general, it can be said that any
preparation in electronic format doubles the time spent. This
applies to all the types of documentation, also, for instance, the
administration around the lectures.
A lecture load of 12 hours means that it is a full job and doesn't
leave any time for science. Only after some years, when a stable
position has been won at the department with respect to the DSD
(distribution of services of docents), a little more time was
liberated for science.
However, preparing the lectures well gives more peace of mind when
talking in Portuguese in front of a class. Moreover, students at a
university deserve high quality lectures. Also, lectures well
prepared gives less work in following years. This shows once more
the importance of having a stable DSD for the quality of education.
I always prepared my lectures in the best possible way. Add to this
the fact that "knowledge should not only be hunted for the love of
knowing, but also to share it with your own brothers" (Umberto Eco
in The Island of the Previous Day). My background is in Physics, but
I am employed in the department of Electronics and Informatics. For
informatics I already had a reasonable knowledge (studied
Experimental Physics, Informatics branch in Amsterdam), but
especially for Electronics I had to study a lot to reach a
Up to this point I have given 16 different disciplines (7 when
considering the months of lecturing in Electronics I in a semester
that changed halfway). Of those disciplines, many of them were my
responsibility. For these disciplines, namely Introduction to
Computing (Introdução à Computação),
Programming I (Programação I,
later renamed Imperative Programming, Programação Imperativa), Electronics II (Electrónica II), Physics of
Electronic Components (Fundamentos
de Componentes Electrónicos) and Electronic Instrumentation
Telecom Network Systems (Sistemas de Redes de Telecomunicações),
I wrote the lecture notes ("sebenta")
and exercises. The Instrumentation is currently written up into a
book to be published by Wiley. The first two are in HTML format for
easy access of the students studying at home and in the classroom.
All the lectures notes were made available on-line not only to the
university students but to everybody in the world, since I am a big
fan of the MIT idea of Open Courseware. All this can be found in the
annex or following the links in the table below. For the informatics
theoretical lectures, initially transparencies were used. For the
other lectures, the blackboard was used. In more recent years
datashows arrived at the university. Powerpoint presentations were
prepared by me for the informatics lectures, see the links below (to
save paper, these are not included in the hardcopy of this
The highlight for 2012 is working
on a book about the lectures of Electronic Instrumentation. This
is a work in progress that is expected to be finished in summer of
2014 and will have about 300 pages.
Finally, it is worth
mentioning that on-line educational software was written
that simulates complicated physical ideas of electronic
components. For compatibility reasons, these simulations
were written in Java applets and were embedded into HTML
pages. Click on the icon Java or follow this link to see the
On the CD it can be found here.
Other pedagogic activities
Final Year Projects:
José Almada and Nelson Pimenta, Final-year project of
ESC named "Measuring FET parameters as a function of frequency" (Parâmetros de FET's em Função de
Frequência), 4 November 2003.
Diogo Emanuel de Moura Lobo and Carlos Miguel Fernandes Dias,
Final-year project of ESI named "Implementation of QCM mesaurement
In 2005, a student from Ryszard Łazarski University of Commerce and
Law visited me to do a one month stage in OptoEl.
(Co)Supervisor of PhD student, João Encarnação, "Development of
biosensors for the malaria setting", SFRH/BD/12772/2003. Graduated
January 2008 Thesis title: "Development of
Biosensors for Molecular Analysis".
Supervisor Starting Investigator (BIC) André Romão, 2005.
In 2000, I was invited to give lectures at the SELOA Summer School
in Bologna. The details of the lecture and the link to the handouts
"Electrical Characterization of Organic Semiconductors", Peter Stallinga, 2000.
Later an additional document in the same style was added:
"Theory of (organic) (thin film) Field-Effect Transistors", Peter Stallinga, 2004.
Finally, I guided two students of the course of Informatics Teaching
(Ensino de Informática) and
evaluated them when they were doing their stage on a secondary
school in Odemira. This involved going to the school and sitting-in
at their lectures and determining their (scientific) quality. In
this way I got an idea about the educational system of Portugal.
Some interesting aspect about the total arbitrariness of the
lectures atributed by my colleagues to their students. See document
Vice Course Director (Subdirector de Curso) of the
course LESI (Licenciatura de
Engenharia de Sistemas e Informática, formerly known as
ESC, Engenharia de Sistemas e
While being vice director of ESC/LESI, I helped in the organization
of the department, for instance in the open days and other forms of
advertising our courses. Examples are the design of the brochures
for LESI in 2004 and 2005, see attachments and . Course Director (Director de Curso) of the
course LESI in 2006. Member of the course direction (Direcção de curos) of the
course Physics 2009-2012 Course Director (Director
de Curso) of the course MIEET, 2013-
Organisation of the books.
For the past years, I was responsible for the organization of the
acquisition of new books for the department.
Cientific Councils. As any
other doctorate member I participated in the departments
administrative bodies of the Scientific Council (Conselho Cietífico) of the
department DEEI and the faculty FCT. I attended most of the meetings
to which he was invited.
Network meeting organizer.
Helping organizing network meetings for SELOA and MONA-LISA (2001).
Twice the European network held a meeting in Faro. First the SELOA
network and later the MONA-LISA network.
6. Other activities
spin-off company, named Vinyar, was started that addresses
the problem of air quality control at wine production
facilities. The problem consists
of the airborne fungi that enter the bottle at the time of
botteling of the wine. It is estimated that some 1% of all
wine in Portugal is lost every year due to this problem.
In a country with a substantial wine industry -- of about
1 billion euros per year -- this is obviously a huge
problem. The direct damage is in the order of tens of
millions of euros per year, but the damage goes much
beyond direct physical damage. Every bottle that is opened
and that smelss of 'rotting cork' destroys the image of
the wine house and should thus be avoided at all cost. The
idea is to develop sensing systems to detect and eliminate
the main agent causing this failure of wine. See the
business presentation here.
Finally, work that doesn't fit in the catagories above (scientic,
pedagogic or administrative), but which is worth mentioning is the
CAD (computer-aided design). I designed the logos of the
Opto-Electronics and Organic-Electronics laboratories as well as the
CEOT research center (and also the Vinyar logo above):
Opto-El. logo was designed in
1997 and is based on the logo of The University of The
Algarve (see in the beginning on the right of this
document). The Univeristy logo with its excentric circles
symbolizes the spreading of knowledge in the direct area of
the university, namely The Algarve. The Opto-El logo
incorporates the university logo which represents that
Opto-El wholeheartedly supports the idealogy of the
university. The electronic components added to the
University logo represent the electronic nature of the
laboratory. Moreover, the FET, in series with an LED and
ground symbolize that "While we have everything under
control, we are brilliant, but remain with our feet on the
The resulting mono-chrome image is very modern and is also
good when printed in black and white or in inverse colors.
The disadvantage is that it is a little too detailed and as
such doesn't follow modern design conventions, which favors
simpler designs. Moreover, the lines of the electronic paths
are too thick.
The logo was designed with the PjotrSoft (Peter Stallinga)
PASCAL graphics toolbox (EPSTool) with output in
The CEOT logo was designed at
the onset of the research center, in 2001. The three facets
of the cube represent the three legs of the research center,
namely Electronics, Opto-electronics and
Tele-communications. Later, in practice, the legs have
integrated and the edges have blurred. The sphere with the
C, in comparison to the cube being of different geometric
shape, symbolizes that were are not uniformist and can
approach a problem in many ways and shows the strength of
the research center.
The combination of the sphere and especially the cube gives
the logo a three dimensional character and, adding to this,
the pastel colors gives it a pleasant look. Moreover, the
logo lends itself very well to manipulations in the modern
informatics world (read internet pages), see for instance
the CEOT pages, but is less adequate for black-and-white
representations. For this purpose (hardcopy commucations) a
mono-chrome version was designed contemporarily.
The logo was designed with Corel Draw 8 (due to font
incompatibilities in the Corel Draw versions, it is no
longer readible in version 10).
The OrgEl logo was designed
in 2009 and once again it is based on the University logo of
the four excentric circles. The idea was to use the same
'atmosphere' of the rings that can be seen as the letter 'O'
and use the same style to write a letter 'E', thus forming a
acronym OE. The logo was designed using EPSTool with output
in (Encapsulated) PostScript.
Modern design with
social-networks-badge-like round aspects and minimal on the
colors. A bunch of grapes composed of benzene rings with a
alhohol stem to show the link with chemistry.