News from the Semiconductor Group

The year 2002 was another busy and productive period for our semiconductor group (Hongxing Jiang and Jingyu Lin). The U.S. Patent Office has issued a patent for our invention of the semiconductor microdisplay. Several companies have already expressed interest in pursuing the technology to bring it to commercialization. In the last issue of Physics Newsletter, we reported that our group was initiating a new research project in the area of III-nitride ultraviolet (UV) photonics for bio-threat detections. Our group's involvement in this nationwide effort, which is currently funded by DARPA, was reported by some of the major media outlets including The New York Times, USA Today,, and during November 2002. The project is progressing well, but is technically very challenging. We have been seeking innovative new approaches to overcome some of the greatest difficulties. We have developed III-nitride UV micro-size lens arrays with individual lens sizes as small as 10 microns in diameter and focal length varying from 7-30 microns for coupling light in and out, as well as for enhancing the optical sensitivities of the III-nitride UV micro-size detectors and emitters. We have also successfully achieved, for the first time, nano-fabrication of III-nitride photonic crystals operating in the blue and UV spectral regions with air holes as small as 100 nanometers; furthermore, an unprecedented enhancement factor in quantum efficiency has been realized.

In collaboration with KU and funded by NSF (Information Technology Initiative program), we are also developing innovative integrated photonic devices based on III-nitride semiconductors for optical communications. The success of this project could provide revolutionary advances in optical communications.

With continuous strong support from several federal funding agencies, we are further expanding the laboratory infrastructure for advanced semiconductor research. The third commercial MOCVD system capable of producing simultaneously 6 pieces of 2-inch III-nitride wafers (successfully installed in May 2002) is running well and producing high quality III-nitride crystals. Other new facilities added to our lab include a deep UV photolithography system for micro-size device patterning with a 0.25-micron resolution, an X-ray diffraction (XRD) spectroscopy system for material structural characterization, and a deep UV near-field scanning optical microscope for nano-scale optical studies. Our unique capabilities for semiconductor material growth, micro- and nano-device fabrication, and fundamental property measurements have placed K-State in a unique position for advancing III-nitride wide bandgap semiconductor research.

Our group's research has evolved successfully from basic physics studies to a comprehensive program that encompasses fundamental physics, state-of-the-art epitaxial material growth, as well as advanced micro- and nano-photonic and electronic device fabrication. More specifically, our current research covers the development of semiconductor UV light sources for biological threat detection and for solid state lighting, integrated photonic devices for optical communications, high power electronics for wireless communications, and microdisplays for image processing. In this way, we are preparing our students with cutting-edge technological skills for the ever-changing scientific world.