Technical: This project seeks fundamental understanding of semiconductor nanowire growth by Vapor-Liquid-Solid and Vapor-Solid-Solid growth processes of Group IV and Group III-V materials. Semiconductor nanowires are one of the primary nanostructured materials under investigation in the field of nanoscience. Because of their compatibility with existing device processing methods and control over their electronic properties by way of diameter selection, doping and heterostructure creation, they hold promise as active elements in future electronic and optoelectronic devices. The project aims for new insights and new knowledge to provide an atomic level understanding leading to development of nanowire integration methodologies. The approach is to use real-time transmission electron microscopy techniques (TEM) to quantitatively characterize the dynamics of semiconductor nanowire growth. Utilizing a combination of ultrahigh vacuum and low-pressure chemical vapor deposition methods, group IV and group III-V nanowires will be grown in-situ in a TEM enabling observation of nanowire growth in real time and at high resolution. Areas of study include crystal growth kinetics, the role of catalyst diffusion, interdiffusion during heterostructure formation, defect formation mechanisms, and nucleation processes.
The project addresses basic research issues in a topical area of materials science having high potential technological relevance. The research will contribute materials science knowledge at a fundamental level to new understanding and capabilities in electronic devices. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. Nanoelectronic devices offer the hope of allowing advances beyond the limits imposed by traditional lithographic fabrication methods. Based on their research outcomes, the investigators will work with a scientific visualization company (Seyet, LLC) to develop realistic animations of nanowire growth. These animations will be incorporated along with more technically descriptive information and video footage to create self-contained modules for dissemination through Purdue's Freshman Engineering curricula and the Purdue-based online "NanoHub" resource.
