A Simple Integratable Silicon Photodetector Covering the Short‐Wave Infrared and Optical Communication Bands at 1.3 and 1.55 μm

Silicon photodetectors and camera chips are ubiquitous in the visible region of the spectrum and the near‐infrared. However, their large bandgap prevents their use at longer, technologically very important, wavelengths. The band‐edge‐modified rare‐earth detectors in silicon demonstrated here, fabricated using standard silicon technology tools, offer a route to these wavelengths and room‐temperature operation. Ion implantation of the usual n‐ and p‐type dopants, arsenic and boron, into commercial silicon wafers is used to fabricate a standard silicon p–n junction. Further implants of the rare earths, either Ce or Yb, are made into the depletion region to enable the extended long‐wavelength response. Detectivities up to 1.47 × 108 cm Hz1/2 W−1 and 2.89 × 107 cm Hz1/2 W−1 at 1.3 and 1.55 μm have been obtained with these simple planar devices. If integrated as lateral detectors in a silicon photonics platform, responsivities as good as standard silicon photodetectors in the visible and near‐infrared will be achievable.