Si-based blue light emitting diode
Abstract
Phase 1 results demonstrated for the first time a strong, stable blue-green emission from C-implanted red-emitting porous silicon. The objective of Phase 1 was to obtain blue-green emission from porous Si structure either by increasing the bandgap of the substrate by growth of Si-C random alloys prior to forming nanostructures with quantum confined properties, or by increasing the confinement energy of red-emitting Si nanostructures. Porous structures fabricated from group 4 alloys epitaxially grown by chemical vapor deposition (CVD) resulted in an enhancement in light emission of about one order of magnitude after incorporation of a very small amount of carbon in the epitaxial grown films. Strong blue-green light emission was observed by the naked eye from C-implanted and annealed porous Si. Using AlGaAs as a reference, we observed that the intensity of blue-green emission was one order of magnitude higher than that of the original red-emitting porous Si. Catholuminescence measurements of our samples performed at the University of Colorado show blue emission at 1.80 eV and 2.80 eV. Fourier transform infrared (FTIR) spectra of a blue-green emitting porous structure shows an IR absorption line identical to that of SiC and electron diffraction studies clearly show reflections corresponding to beta-SiC. Phase 1 results indicate that blue-green light is from SiC nanostructures with quantum confined properties. This material may be used to fabricate blue light-emitting Si-based devices which can be easily integrated into Si technology.
- Publication:
-
Final Technical Report
- Pub Date:
- May 1994
- Bibcode:
- 1994spco.reptS....N
- Keywords:
-
- Aluminum Gallium Arsenides;
- Color;
- Electron Diffraction;
- Energy Gaps (Solid State);
- Infrared Spectra;
- Light Emitting Diodes;
- Porosity;
- Silicon;
- Stability;
- Vapor Deposition;
- Infrared Absorption;
- Line Spectra;
- Electronics and Electrical Engineering