Band Gap Engineering of Advanced Photodetectors via Quantum Size Effects in SiC Nanostructures

The proposed research addresses the critical need for the development of an advanced sensor technology for ballistic missile defense applications. The proposal is aimed at investigating the unique physical processes which occur in wide band gap (WBG)semiconductor nanostructures due to quantum confinement effects. Silicon carbide, an attractive high-temperature, radiation hard semiconductor, which has already been proven to be a perfect electronic material for the UV photodetection in harshenvironments, is chosen for the proposed investigation. SiC periodic nanorods with controllable lateral dimensions on the 5-50nm scale will be fabricated using a novel, ultra-high precision technique. High fidelity reactive ion etch of SiC epilayers willbe carried out employing a molecularly self-assembled mask, which will allow an unprecedented atomic-level control over the lateral dimensions of nanorods as well as the spacing between them. Structural, electronic and optical properties of the fabricatednanostructures will be systematically investigated in order to establish fundamental relationships between their dimensions and spatial distribution and their optoelectronic and sensing characteristics. These studies will focus on the quantumconfinement-related effect on the band gap, and nanorod density on cooperative electronic coupling. It is expected that an advanced model for band gap tuning with improved sensing capabilities for SiC detectors will be developed in the proposed research.The Phase I effort will focus on demonstrating the tunability of SiC band gap and control over the detection limits and sensitivity via nanoscale engineering.Band gap engineering employing quantum confinement effects in wide band gap semiconductornanostructures will lead to significantly improved detection capabilities for the many ballistic missile and other defense applications, as well as for the space-related projects, which makes it interesting to NASA and manufacturers such as LockheedMartin, Hughes, and Rockwell International. It will also be of great interest to the image processing industry including Xerox, Kodak and Polaroid. The nanowell technique for the fabrication of periodic nanostructures will have a wide breadth of potentialapplications in commercial microelectronics industry, where the potential customers include IBM, Intel, Motorola, and other similar microelectronics manufacturing organizations.