In this paper, a methodology for the analysis of a resonant cavity enhanced (RCE) photodetector, based on internal photoemission effect and working at 1.55 μm, is reported. In order to quantify the performance of photodetector, quantum efficiency including the image force effect, bandwidth and dark current as a function of bias voltage are calculated. We propose a comparison among three different Schottky barrier Silicon photodetectors, having as metal layers gold, silver or copper respectively. We obtain that the highest efficiency (0.2%) but also the highest dark current is obtained with metal having the lowest barrier, while for all devices, values of order of 100GHz and 100MHz were obtained, respectively, for the carrier-transit time limited 3-dB bandwidth and bandwidth-efficiency.