High-speed GaAs PIN photodiodes grown on Si substrates by molecular beam epitaxy

The potential integration of the optoelectronic capabilities of GaAs with the highly developed integrated circuit technology of Si has motivated a great deal of effort toward fabricating GaAs devices—particularly lasers—in epitaxial layers grown on Si substrates. A GaAs-on-Si detector can take advantage of the high carrier mobilities and optical absorption coefficient of GaAs and serve as a high-speed receiver in a composite GaAs/Si optoelectronic circuit.