Ku abstract-SJTU - University of Michigan

Nanostructured Nitride Semiconductors and Their Applications
P.C. Ku (古培正)
Department of Electrical Engineering & Computer Science, University of Michigan
In this study, we focus on potential applications of gallium nitride semiconductor nanostructures
for future display, wearable technology, photovoltaics, biosensors, and quantum cryptography.
The key is the ability to control the strain in these nanostructures. Strain can alter both electronic
and optical properties of semiconductors. Properly controlled, strain can greatly improve device
performance. Poorly controlled, strain increases defect density and leads to unwanted properties
such as efficiency droop in LEDs, difficulties in achieving green emitters, and abnormally large
linewidth from quantum dot emission. In this work, we study the impact of strain in nitride
semiconductor nanostructures on their optical properties. We have shown the exploitation of
strain can lead to monolithic integration of RGB emitters and a lower defect density in nonpolar
GaN films. High indium content InGaN nanostructures have also been demonstrated for
photovoltaic applications.
P.C. Ku is the associate professor of electrical engineering and computer science
at the University of Michigan. He received all his degrees in electrical
engineering including a BS from the National Taiwan University and a PhD from
the University of California at Berkeley. Dr. Ku has a long career in the field of
optoelectronics, starting in 1995 when he joined the lab of Professor Ching-Fuh
Lin of the National Taiwan University as a research assistant. After two years
of military service as a Navy ensign, he became a full-time student again in 1998
under the guidance of Professor Connie Chang-Hasnain at the University of California Berkeley.
His doctoral dissertation is on semiconductor slow light devices. He was among the first to show
that the speed of light can be significantly reduced in a specially designed semiconductor
structure. As a result of his PhD research, he was awarded the Ross Tucker Memorial Award in
2004. During his PhD study, Dr. Ku was the recipient of the Berkeley Fellowship. After
receiving his PhD, Dr. Ku spent two years both as a postdoctoral researcher for the DARPA
Center for Optoelectronic Nanostructured Semiconductor Technology and as a senior engineer
for Intel. His research shifted from telecommunication devices to optical lithography and phasechange memory. It was during this time Dr. Ku conceived the idea that advanced lithography
technology can be revolutionary to optoelectronic devices. In 2006, he returned to academia as
an assistant professor of electrical engineering and computer science at the University of
Michigan. His research has since been focused on creating impacts for optoelectronic devices in
the emerging areas of energy, quantum, and biomedical science. He has worked on a variety of
projects funded by NSF, DARPA, and DOE including LEDs, solar cells, nanoscale lasers,
biosensors, and single photon sources. He received the DARPA Young Faculty Award in 2010.