Near infrared microstructured Si-PIN photodetector with high photoresponse and low dark current

In this study, spike microstructures with different sizes are prepared on the surface of Silicon-based detectors via fs-laser. We then investigated the effect of the laser-textured conical microstructures on electrical characteristics of the microstuctured silicon-based photodetector. The interaction mechanism between the hyperdoping surface-layer and the conical microstructure was studied by using a finite-difference time-domain method. Furthermore, we propose a method of equivalently thickening the hyperdoping layer and remove surface defects by double-sided fs-laser-texturing combined with RIE treatment to effectively enhance the near-infrared optoelectronic properties of silicon-based detectors. The 1064nm photoresponse at 0.1 V reverse bias and the dark current at 5 V reverse bias of the novel silicon-based near-infrared photodetector fabricated by this method are 0.56 A/W and 3.6 NA, respectively.