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Friday, October 31, 2014
LPTH Press Release: LightPath Technologies Schedules Fiscal 2015 First Quarter Conference Call
Tuesday, October 21, 2014
Distinguished Seminar Series: "Field-Effect Liquid Crystal Displays, LC-Materials & Optical Alignment of LCs" by Martin Schadt 11.14.14/12:00-1:00pm/ CREOL 103
Distinguished Seminar Series: "Field-Effect Liquid
Crystal Displays, LC-Materials & Optical Alignment of LCs" by Martin
Schadt
Friday, November 14, 2014 12:00 PM to 1:00 PM
CREOL Room 103
CREOL Room 103
Dr. Martin Schadt
MS High-Tech Consulting, CH-4411 Seltisberg, Switzerland
Abstract
Since the invention of the twisted nematic (TN) field-effect
in 1970, the nematic liquid crystal display technology which is based on
electric field-effects has made remarkable progress. Field-effects are
characterized by polarization sensitive macroscopic molecular liquid crystal
configurations with electrically tunable optical appearance.
The unique electro-optical building block concept of
field-effect LCDs enables the integration and individual optimization of
anisotropic optical thin-films and silicon electronics in LCDs. The remarkable
progress made over the past 45 years, renders today virtually all applications
of the communication between man and machine possible. They range from
reflective LCDs with “zero power” consumption, such as digital watch LCDs, or
remotely controlled electronic price tags in Shopping centers, to iPhones and
large size, ultra-high resolution 4k television LCDs. Since the beginnings in
1970 this development has been spurred by interdisciplinary R&D between
physics, material sciences, synthetic chemistry, semiconductor electronics, and
engineering. It includes TN-LCDs (1970), super-twisted nematic (STN)-LCDs
(1980s), thin-film transistor (TFT)-addressed TN-LCDs for computer monitors in
the early 1990s and beyond, and multi-domain LCD configurations. The latter
became possible in the late 1990s either by electric fringe-field electrode geometries,
or by photo-alignment/patterning of LC molecules. Further enhanced contrast,
large angles of view and shorter response times were the result. Moreover,
spin-offs into potential future types of field-effect LCDs, such as polymer
stabilized blue phase LCDs and ferroelectric LCDs became possible.
This development is reviewed with examples of the
multidisciplinary R&D of the author and collaborators on electro-optical
field-effects, liquid crystal materials and polarized optical alignment and
alignment patterning of monomeric and polymeric liquid crystal molecules in
LCDs and optical thin-films based on liquid crystal polymers.
Biography
Dr. Martin Schadt was born on 16th August 1938 in Liestal,
Switzerland. After having gained practical experience as electrician Martin
Schadt majored in experimental physics at the University of Basel, Switzerland,
where he received his PhD in 1967. He was granted a two year post-doctoral
fellowship at the National Research Council, Ottawa, Canada, where he continued
his research on the electronic and optical properties of organic
semiconductors. In 1969 he and D.F Williams patented the first solid state,
organic light emitting display (OLED). Dr. Schadt’s first professional
association was with the watch company Omega, where he investigated atomic beam
standards. In 1970 he joined the Central Research Laboratories of F.
Hoffmann-La Roche Ltd., Basel. Except for two years in biophysics, his research
focused on the development of electro-optical field-effects based on liquid
crystals and on liquid crystal materials. 1970 Dr. Helfrich and Dr. Schadt
invented the twisted nematic (TN)-effect at F. Hoffmann-La Roche. The Roche
TN-field-effect patent was granted in 20 countries and was licensed world-wide
to the emerging field-effect LCD industry by Roche. The invention initiated a
paradigm change towards flat panel field-effect liquid crystal displays (LCDs)
enabling today’s LCD industry. The search for correlations between molecular
structures, material properties and display performance, which Dr. Schadt
started in the early 1970s, enabled the development of new liquid crystals for
TN- and subsequent field-effect applications. As a consequence the
pharmaceutical company Roche established itself as a major liquid crystal materials
supplier for the emerging LCD-industry. Apart from his pioneering work on
OLEDs, the TN-effect and liquid crystal materials, Dr. Schadt and collaborators
invented the linear photo-polymerization (LPP) technology in 1991 enabling
alignment of liquid crystal molecules by light instead of mechanically. This
opened up novel LCD configurations and LCD operating modes, as well as numerous
anisotropic optical polymer thin-films.
Until 1994 Dr. Schadt headed the Liquid Crystal Research
Division of Roche. Based on its photo-alignment technology the Division was
turned in 1994 into the spin-off company ROLIC Ltd, an interdisciplinary
Research and Development Company which Dr. Schadt built-up and headed as CEO
and delegate of the Board of Directors until his retirement from the operating
business in October 2002. He is now active as a scientific advisor to research
organisations and continues research in collaboration with partner companies as
an independent inventor. He is inventor or co-inventor of 166 patent families
filed in Europe (EP) and holds more than 119 US patents. He has published 191
papers in leading scientific journals, including chapters in 6 books. Dr.
Schadt became a Fellow of the Society Information Display (SID) in 1992 and a
Fellow of the European Academy of Sciences in 2011. He is inventor or
co-inventor of 166 patent families filed in Europe (EP) and holds more than 119
US patents. He has published 193 scientific papers in leading scientific
journals, has given more than 150 lectures and contributed to 6 books. He has
received the following Awards: the Roche Research and Development Award (1987),
a Special Recognition Award and a Best SID Paper Award (1987), the SID Karl
Ferdinand Braun Award (1992). Together with W. Helfrich, he received the Aachener
und Münchener Preis für Technik und angewandte Naturwissenschaften (1994) and
the Robert-Wichard-Pohl Prize of the German Physical Society (1996). Together
with W. Helfrich and James Fergason, he received the IEEE Jun-ichi Nishizawa
Medal (2008). In 2009 he received the Eduard Rhein Technoloy Prize. The G.W.
Gray Medal of the British Liquid Crystal Society and the Blaise Pascal Medal
for Material Sciences of the European Academy of Sciences (2010). The Frederiks
Medal, highest recognition award of the Russian Liquid Crystal Society (2011).
The Charles Stark Draper Prize of the US National Academy of Sciences (known as
the “Engineering Nobel Prize”) together with G. Heilmeier, W. Helfrich and P.
Brody (2012). European Inventor Award 2013 for Lifetime Achievement (2013).
Fellow of US National Academy of Inventors NAI (2013). Honorary Prof. of
Sichuan University, Chengdu (2013). Honorary Prof. of Nanjing University,
Nanjing (2013).
For additional information:
Dr. Shin-Tson Wu
407-823-4763
Monday, October 6, 2014
TODAY!! Seminar: "Semiconductor Nanomaterials for Information and Energy Technologies" by Dr. Yajie Dong 10.6.14/ 11:00-am-12:00pm/ CREOL 103
Seminar: "Semiconductor Nanomaterials for
Information and Energy Technologies" by Dr. Yajie Dong
Monday, October 6, 2014 11:00 AM to 12:00 PM
CREOL Room 103
CREOL Room 103
ABSTRACT:
Low dimensional nanomaterials (1 D nanowires and 0 D quantum
dots) represent important nanoscale building blocks with substantial potential
for exploring new device concepts and materials for nanoelectronics,
optoelectronics and energy technology applications. Three examples will be
presented. First, I will discuss my discovery of unique rectified
silver/amorphous silicon/crystalline silicon (Ag/a-Si/c-Si) crossbar resistive
random access memory (RRAM) effect in c-Si/a-Si core/shell nanowires and provide
a comprehensive comparison between nanowire based and planar silicon based
Ag/a-Si/c-Si RRAMs. The history of how this accidental nanowire based discovery
solved a decades-long sneak current problem in RRAM field and eventually
evolved into a game changing mainstream flash memory successor, Crossbar
Memory, will be presented. Then I will report the experimental realization of
high efficiency single coaxial group III-nitride heterostructured nanowire
photovoltaic devices and light emitting devices. Meanwhile, a universal van der
Waals epitaxial growth strategy for compound semiconductor nanowire arrays will
be discussed. The vision of how the combination of nanowire array growth and
heterostructured nanowire devices could possibly change the substrate limited status
of III-Nitride research fields will be outlined. Lastly, I will present how
quantum dots materials innovation and novel device structure design/processing
helped resolve one long standing issue for organic based light emitting
devices, the efficiency roll off at high driving current density. As a result,
record breaking ultrabright, highly efficient, low roll off inverted red
quantum dot light emitting devices (QLEDs) have been achieved (165,000Cd/m2 at
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Dean & Director, Professor of Optics
407-882-3326
BIOGRAPHY:
Dr. Yajie Dong is an assistant professor in NanoScience
Technology Center of University of Central Florida. He got his BS and MS
degrees in Chemistry from Tsinghua University of Beijing, China. In 2010, he
received his PhD degree from Prof. Charles Lieber's group at Chemistry and
Chemical Biology Department of Harvard University. From 2010 to 2012, he was a
postdoctoral associate working with Professors Yet-Ming Chiang and W. Craig
Carter in the department of Material Science and Engineering at the
Massachusetts Institute of Technology. Before joining NSTC of UCF in August
2014, he worked as a Senior Scientist for QD Vision Inc., a Nanotech Startup
based on research of Professors Moungi Bawendi and Vladimir Bulovic’s groups at
MIT and located in Lexington, MA. He is broadly interested in materials
challenges in nanoelectronics, optoelectronics and energy technologies,
particularly in nanoscale nonvolatile resistive switches for information
processing and storage, compound semiconductor nanowires or quantum dots based
high efficiency energy conversion (LED and PV) devices and new battery
materials and architectures for large scale energy storage.
For additional information:
Dr.
Bahaa SalehDean & Director, Professor of Optics
407-882-3326
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