SiGe and Si Quantum Wires for Efficient, Room Temperature, Tunable Luminescence
Abstract
A porous silicon visible light emitting diode has been developed. Porous silicon was prepared by electrochemically etching p-type silicon wafers in hydrofluoric acid solutions. Photoluminescence spectroscopy of these samples revealed intense light emission at wavelengths throughout the visible spectrum, as well as unusually strong emission at the band edge energy of bulk crystalline silicon Emission intensities were comparable to those usually exhibited by high quality reference samples of GaAs. Thus quantum confinement of carriers in silicon nanostructures, created by the etch procedure, is indicated. Electroluminescence is observed from diode structures fabricated as heterojunctions between porous silicon and the transparent conductor indium- tin oxide, which serves as a window to allow light emission from the top surface of the device. Luminescence only occurs under forward electrical bias, while photovoltaic effects are seen under reverse bias. After the data are corrected for series resistance effects, the electroluminescent devices are shown to operate at junction biases of about 3-4 volts. A model based on minority carrier injection has been developed. Porous silicon light emitting diodes offer great promise for wafer scale integration of optical interconnects in high speed data processor applications, and to allow the construction of low cost flat panel displays, entirely in silicon.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 03, 1992
- Accession Number
- ADA249651
Entities
People
- Fereydoon Namavar
- H. P. Maruska
- Nader M. Kalkhoran