In Search of Luminescence in Silicon
Abstract
Two schemes were studied: (1) IAG-Superlattices (Interface-Adsorbed-Gas) were fabricated in a silicon MBE system capable of exposure to oxygen at 10(exp -7) Torr for adsorption. Si deposition is between 5 to 20nm at room temperature with annealing temperature between 800 to 950C, forming 3nm Si nano-particles. Photoluminescence shows two peaks located at 1.7eV and 2.35eV. The former originates from the interior, whereas the latter from the surface regions of the silicon nano-particles. (2) Si/O Superlattices were fabricated with silicon epitaxial growth (1.1nm) at 550-600C, followed by oxygen adsorption at room temperature. High resolution TEM shows epitaxy, and Plane view TEM shows defect densities, dislocations and stacking faults, below 10(exp 9 )/sq cm. The process is repeated up to 9 periods for photoluminescence, PL, and electroluminescence, EL, measurements. A broad peak located at 1.8eV, originates from quantum confinement in silicon thin layers, and a sharp peak located at 2.2eV, originates from the Si/O complexes. EL is particularly impressive. Greenish light output is stable in a life-test of more than one year of continuous operation. Our results stimulate new views toward physical phenomena originated from interfaces and surfaces: "the overall control and resulting stability allow such devices to be ready for applications".
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 18, 1999
- Accession Number
- ADA371446
Entities
People
- Raphael Tsu
Organizations
- University of North Carolina at Charlotte