Semiconductor nanowires can transport electrons (holes) and excitons and thus are idea building blocks nanoscale optoelectronic devices such as nano light emitting diode (LED) and laser. The bottom-up approach utilizing these nanowires has great potential in future nanodevice technology as it can overcome the economic limitations of conventional lithography-based fabrication. The major problems in achieving nano-optoelectronic devices is the difficulty in realizing p-n junctions in individual nanowires and the lack of understanding of fundamental issues such as their electronic structures and the related optical behaviour. In this project, we will synthesize a series of n-type II-VI compound/p-type Si bi-crystalline nanowires based on a newly developed method. The electronic structures of individual nanowires and their optical properties will be investigated to understand the fundamental factors that decide the final device performance. Finally, proto-type nanodevices will be fabricated using selected nanowires to examine their electrically driven light emitting and possibly lasing properties. [Up to three students may be admitted.]
References:
Q. Li and C.R. Wang, "One-step fabrication of uniform Si-core/CdSe-sheath nanocables", Journal of the American Chemical Society 125, pp. 9892 -9893 (2003).
Q. Li and C.R. Wang, "Fabrication of wurtzite ZnS nanobelts via simple thermal evaporation", Applied Physics Letters 83, pp. 359-361 (2003).
Q. Li and C.R. Wang, "Fabrication of Zn/ZnS nanocable heterostructures by thermal reduction/sulfidation", Applied Physics Letters 82, pp. 1398-1400 (2003).
