| 摘要 |
Si-based photodetectors according to the invention can have high speed (e.g.,>/=1 Gb/s) and high efficiency (e.g.,>20%). The detectors include a relatively thin (e.g.,<0.5 alpha -1, where alpha -1 is the absorption length in Si of the relevant radiation) crystalline Si layer on a dielectric (typically SiO2) layer, with appropriate contacts on the Si layer. Significantly, the surface of the Si layer is textured such that the radiation that is incident on the surface and transmitted into the Si layer has substantially random direction. The randomization of the propagation direction results in substantial trapping of the radiation in the Si layer, with attendant increased effective propagation length in the Si. Detectors according to the invention advantageously are integrated with the associated circuitry on a Si chip, typically forming an array of detectors.
|
