CAREER: Position-Controlled Doping of Semiconductor Nanocrystals

University Of Florida, Gainesville FL

Investigators

Abstract

Technical Abstract The scientific goal of this CAREER project is two-fold: (1) to develop a general approach for making high-quality semiconductor nanocrystals doped with position-controlled impurities, and (2) to systematically study the physical consequences of position-controlled doping in various semiconductor nanocrystals. A three-step colloidal synthesis will be developed for doping semiconductor nanocrystals. In this synthesis, impurity doping only occurs in the nanocrystal growth stage, which allows for the easy control of doping levels and the radial positions of dopants in a spherical nanocrystal. The ability to control these material parameters will create a new opportunity to tailor the optical, electronic and magnetic properties of semiconductor nanocrystals. The successful application of this research will provide a new type of doping-based nanostructure for developing technological applications in biomedical diagnosis, photocatalysts, solar cells, LEDs, spintronic devices, etc. These nanocrystals will also provide unique, nanometer-scale semiconductor systems for systematically elucidating the fundamental interactions between quantum systems and position-tunable dopants. This advance will open a new direction to the rational design of functional nanomaterials, and it will further create new opportunities for nanocrystal-based applications. In the area of education, this CAREER project develops nanotechnology education for students at various levels: (1) undergraduate curriculum development for analytical chemistry, (2) a new graduate course on nanotechnology, and (3) nano-synthesis experiments for high-school students. Non-technical Abstract As one of the most exciting frontiers in modern science, nanoscience has created opportunities to profoundly impact technologies that run the gamut from labels for disease diagnosis to high-density data storage for computers and other consumer electronics. To produce such advanced technologies requires totally mastering the science of fabricating nanomaterials with new functions, which is the subject of this CAREER-development project. This project outlines three broad scientific tasks: (1) radial-position-controlled doping of semiconductor nanocrystals with magnetic impurities; (2) doping of semiconductor nanocrystals with conventional impurities; and (3) co-doping of semiconductor nanocrystals with magnetic and conventional impurities. The proposed research work will lead to a new type of doping-based nanostructure for developing technological applications such as highly sensitive biomedical diagnosis (for early-stage detection of cancer), more efficient solar cells, and spintronic devices for the next generation of computers. This CAREER project takes place in the field of nanotechnology at the intersection of chemistry, physics, and material sciences. The multi-disciplinary nature of this project makes it unique for educating students (at the high-school, undergraduate, and graduate levels) with the necessary knowledge, understanding, and skills to provide leadership in the emerging world of nanotechnology.