An interview with Chairman Hsiang Chen

My PhD studies consisted of investigations into the reliability issues of Gallium Nitride (GaN) devices and materials. Gallium Nitride is also an optical material, used in the composition of GaN LEDs. In an LED, when the anode is connected to a positive bias and the cathode is connected to a negative bias, the device will illuminate and shine. On the other hand, if it is connected in the opposite way, that is, the anode to a negative bias and the cathode to a positive bias, LED will not emit light. This is known as a reverse bias connection of a PN junction. In actuality though, it will illuminate very dimly when the device is reversely connected.

Observing the illumination of an LED by an Electron Multiplying Charge Coupled Device (EMCCD), any defects inside an LED will shine, and can be monitored. Moreover, the devices investigated during my PhD research were more than LEDs; they were also high-power GaN transistors, which are components of a cellular base stations or satellites that require high-power transmission. These transistors aren known for having some reliability problems and defects, and I used optical methods to examine both defects and reliability issues.

 After I finished my dissertation and received my PhD degree, a German publisher, VDM, wanted to publish my doctoral dissertation, about the yellow luminescence defects inside GaN transistors.

I accepted the publisher’s offer, and the dissertation was sold on Amazon, the largest book selling website in the world.

 My current research is investigations into ZnO nanomaterials. The shape and morphology of ZnO rods are hexagonal pillars, like the basalt formations we can see on Penghu or Jeju Island, Korea. Zinc oxide rods or nanorods are the same structure as the basalt pillars seen on the two islands, but the size is around ten thousand times smaller than that of those hexagonal pillars. These ZnO nanomaterials have a great advantage of a large surface areas, which are suitable for use as sensors. These nanomaterials can be used for low-cost, high efficiency and compact-sized gas and light sensing devices because their volume is very small, allowing the sensors to be portable. In our current research, we are actually making some very simple changes to these nanostructures, transform these nanorods into hollow nanotubes. We are also incorporating some additives into these nanomaterials such as graphene, metallic nanoparticles, or carbon nanotubes (CNTs) to enhance sensing performance and reliability.   

In addition to do research in the nanoworld, we are also participating in a University Social Responsibility project. Using our expertise in optical technology, we installed LED devices around the fields to promote the growth of white bamboo shoots and passion fruit. By taking part in this project, we have provided job opportunities to optoelectronic and applied materials students, enabling them to make connections and integration with the agriculture and photonic industries in Nantou County.

Our principal has famously said, "Teaching is the foundation, and research is the root." The employment trends in the optoelectronic and semiconductor engineering industry is actually very promising, not only in Taiwan, but also abroad. Now we must start by laying a solid foundation for our students. One day in the future, they will be the mainstream engineers in Taiwan and around the world. Second, our teaching must be adhere to the most recent technological developments of our cutting-edge semiconductor industry, so what we teach in class should not only be formulas and the theories; we should also transmit our knowledge to our students in ways that can be useful for their future job performance. Third, how can our teaching be connected to the research of recent Noble prize Laureates? As our students pursue master's and doctoral programs in the future, a solid foundation of knowledge will foster their advanced research. Finally, the current optoelectronics industry actually consists of three parts: light emitting technology, such as LEDs, energy storage technology related to light absorption, such as solar cells, and display technology, such as monitors.

 I personally believe that our students have a very bright and shining future ahead of them. If students can gain solid, fundamental semiconductor knowledge and be trained to fabricate versatile materials and optoelectronic semiconductor devices, they can cross the threshold of semiconductor technology and be capable of integrating electronic, optical and material fabrications with the solid knowledge of fundamental physics, chemistry, and math. Our students’ future is broad, and employment opportunities are also very promising. Their future path is bright and they have the potential to illuminate the world.