Pore size dependence of PtSi/Porous Si Schottky barrier detectors on quantum efficiency response

The paper describes how pore size and geometry of porous silicon can affect the electrical and optical properties of PtSi/Porous Si Schottky barrier detectors. In this study, two techniques used to prepare different porosities on silicon substrate which includes: electrochemical etching process and electroless metal-assisted chemical etching. Surface morphology and geometric properties of PtSi/Porous Si have been characterized using scanning electron microscopy (SEM) and also I–V characteristics of detectors at reverse bias performed at cryogenic temperature 77 K; between 1–5 μm for IR spectroscopy measurements. It was found that by reducing the overall size of pores from micrometric to nanometric size, the external quantum efficiency increases up to 80% for 1 μm radiation and the wavelength of maximum responsivity moves toward the lower IR spectra in 77 K. Furthermore, the produced micro metric pores using electrochemical porosification, show more constant responsivity than nanometric one's which obtained from metal-assisted chemical etching.