Design and Electro-Optical Characterization of Si-Based Resonant Cavity Light Emitting Devices

The fabrication and characterization of electrically pumped silicon/silicon dioxide (Si/SiO₂) Fabry-Perot microcavities is reported. The active region of these devices consists of an Er-implanted silicon-rich oxide (SRO:Er) film placed in the center of a λ-cavity polysilicon spacer. The structures have been designed in order to enhance the electroluminescence signal at 1540 nm, which is an important wavelength for telecommunication systems, and to achieve high directionality and high-purity spectra. The active region design allows the Er-implanted SRO film to be driven electrically. These Si-based resonant cavity light emitting diodes are fabricated by chemical vapor deposition on a silicon substrate. Microcavities with a quality factor ranging from 50 to 118, depending on the number of Si/SiO₂ pairs constituting the dielectric mirrors, have been fabricated. Low operating voltages and electrical stability have been achieved. The emitted power versus current flowing in the active medium was measured for the structures with different quality factors. An enhancement of the electroluminescence signal at the selected emission wavelength was achieved with a proper design.