Direct electro-optical actuation in silicon

Light emitting diodes have been fabricated in silicon using p/sup +/n/sup ++/ diodes that are operated at avalanche breakdown. The poor electro-optical conversion efficiency remains the limiting factor and precludes application in large integrated displays. The optimum doping profile of the avalanche diode for light emission depends on the application. A maximum concentration is required at the surface for application in a display and the maximum should be designed in the bulk of the silicon when silicon integrated optics or optocouplers are to be fabricated. Interesting display applications are the presentation of prober data during slicing and bonding under a microscope. The main part of the emitted spectrum is in the near-infrared. The performance of the avalanche light emitting diode in a silicon optocoupler has been experimentally verified. The experiments also indicate good prospects for application in silicon integrated optics.<>