Let’s talk about your background. From a village
boy in Yuen Long to the “Father of OLED”, you
have experienced quite a transformation in your
life. What do you think are the major driving
forces that have contributed to your success
today? Who has the most influence on you
throughout the process?
As a boy I enjoyed the simple village life. The
village was a small community with a dozen families
or so, all working in the field and raising farm
animals for a living, including my mother who ran
the farm while my father managed a shop in town.
The village locals led fairly hard lives, but by and
large they were self-sufficient. At the time (mid
1950’s) the village has not yet been electrified. I
remember one of my jobs was to light kerosene
lamps around the house in the evening. When
electricity finally came to the village, I was
fascinated by how easy it was to turn on the lights.
More so, I was happy that I never had to light
another kerosene lamp! And living in a farm, I had
to help out in the rice field. I dreaded weeding with
my bare hands and bended knees in the muddy
field, so I came up with a raking tool made of scrap
wood and nails to do the job standing up. I was
delighted that the simple tool worked and made
working in the field a little more tolerable. It seems
that I have learned a valuable lesson quite early in
my life - to get things done with less work.
For the most part my early schooling was ordinary.
Somehow I managed to get by as an average
student, more interested in kicking football than
hitting the books. That changed when, at 16, I was
enrolled in the Yuen Long Public Middle School for
the last two years of high school. I noticed that
there were quite a few smart students in my class
and they were dead serious about school work.
The peer pressure was intense and I felt I had to
study just to keep up. Indeed my fellow students
inspired me to turn to books and I found my
interest in science. I managed to do well enough in
this school to earn the opportunity to complete my
matriculation at King’s College, one of the top
high schools in Hong Kong.
After getting a BS in chemistry at the University of
British Columbia in 1970, I ended up at Cornell
doing my PhD with Professor Andreas C. Albrecht.
It was an incredible experience working with a
brilliant scientist, a critical thinker, and above all, a
kind and compassionate human being. The five
years I spent in Albrecht’s research group was like
embarking on a journey in both science and
humanity with a wise guide who would help chart
the course with me but let me take the helm to
experience the discoveries on my own. At the end,
I felt I had learned enough to take on future
adventures on my own. Albrecht has impacted my
life and work in so many ways that I only hope I
can pass them on to my own students.
You first “connected” with HKUST as an IAS
Visiting Professor back in 2011, and later on
became the IAS Bank of East Asia Professor and
Chair Professor of Electronic & Computer
Engineering, Chemistry, and Physics in September
2013. Having spent more than 40 years in the US,
why did you decide to come back to Hong Kong
and in particular to join HKUST/IAS?
Coming back to Hong Kong is like coming home. I
spent the first 20 years of my life in Hong Kong, but
I have spent many more years outside. I see coming
back to Hong Kong as an exciting adventure in a
familiar home territory, and I certainly hope it will be
a worthwhile experience of discoveries and
enrichments that I can relate to as a native.
As a scientist and engineer, I am naturally drawn to
HKUST. In its brief history, HKUST has become one
of the best science and technology universities in
the world. Personally I have come to know a few of
the faculty members very well. Among them are
Prof Hoi-Sing Kwok, Prof Man Wong, and Prof
Vladimir G. Chigrinov of Electronic and Computer
Engineering. We have significant overlap of interest
in flat-panel display research, and I am hoping to
build on our expertise and experience to establish a
center of excellence in display research that will
ultimately benefit the university and the display
industry in Hong Kong and China. An important
reason for joining HKUST is IAS. By being appointed
one of the first IAS Professors, I am both humbled
and honored. I am aware of the opportunities and
challenges to help build IAS as a world-class
research institute that will be relevant to HKUST and
Hong Kong. I look forward to working with my
colleagues at IAS/HKUST to fulfill this mission in the
years ahead.
Would you please share with us your grand plan
with HKUST and IAS? Are there any specific
expectations which you wish to highlight?
My research will be on display technology. In
particular, I will focus on OLED research, which has
always been my interest. There is a rapidly growing
industry based on OLED and a lot of money has
poured into building up OLED manufacturing
infrastructure in Asia Pacific region. China in
particular is gearing up for manufacturing,
although they are a late comer and their OLED
R&D’s have yet to match those in Korea, Japan and
Taiwan. Our plan is to establish a display research
center that will lead OLED research and
development and help grow OLED industries in
Hong Kong/China region. Despite its many
advantages, OLED has a basic liability – insufficient
lifetime, particularly for the blue emitter. If not
solved, this liability could limit applications that
require high brightness and long durability, such as
HDTVs. Solving this problem will require material
and device research. Another major issue is cost.
To reach manufacturing cost parity with LCD,
OLED cost must be reduced by 2 or 3 folds, at
least for HDTVs. One of our goals is to develop a
low-cost method for patterning large-area OLED
displays, a bottleneck in OLED TV manufacturing.
Our ultimate goal is to make OLED more robust
and affordable. To this end, I envision strong
collaboration with Prof Hoi-Sing Kwok and my
colleagues in HKUST specialized in display
research to come up with creative solutions. I also
expect our center to be a fertile training ground
for researchers in display and related science and
technology.
As a pioneer researcher, what suggestions you
would have for the younger generation researchers
in their quest for scientific discoveries?
Looking back at my own experience, I would have
to say the discovery and development of OLED was
a process of mostly perspiration with a few
inspiration moments. I was fortunate to be the
person to discover the device structure that formed
the basis of OLED, but I must acknowledge that it is
the effort of many people over many years that has
brought us today’s OLED technology. I don’t know
if I have particular wisdom to dispense on scientific
discoveries in general, but I do know working long
and hard is essential as there are usually no quick
and easy fixes for a difficult (and likely more
interesting) problem. Often finding the solution is
like wading through a zigzag path by taking two
steps backward to make a step forward, even with
the help of many people. Of course, the Eureka
moment is always the driving force, however
tedious the process is in getting there. It is highly
satisfying to experience that moment in person.
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What is OLED?
OLED stands for Organic Light Emitting Diode. In its most basic form, OLED is made of two thin layers of organic
semiconductors - a p-type layer for transporting positive charges and a n-type layer for transporting negative charges -
sandwiched between two electrodes - an anode and a cathode. When a voltage is applied to the electrodes, positive
charges are injected from the anode and negative charges are injected from the cathode. These positive and negative
charges recombine at the interface between the organic semiconductor layers to produce light - termed
electroluminescence. OLED is regarded as green technology because it is highly efficient in generating light, using
mostly carbon based synthetic materials. Currently OLED is mostly used for display applications. It is envisioned that it
will have significant impact on energy saving for future lighting applications.
Another honor
For his pioneering work on
OLED, Prof Tang has been chosen
as the 2014 Nick Holonyak Jr Award
winner. This award is presented by the
Optical Society of America (OSA), a
scientific society on optics and photonics
founded in 1916, to an individual who has
made “significant contributions to optics
based on semiconductor-based optical
devices and materials, including basic
science and technological applications.”
The award is named to honor Nick
Holonyak Jr who invented
light-emitting diode
(LED).
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IAS Chatroom
IAS Chatroom
Sep 2014
Sep 2014
