Enhanced silicon bandgap by platinum diffusion for UV detector

Abstract

This research article proposes a new method that enables silicon to respond to light in the UV wavelength range by doping Platinum (Pt), which is an impurity atom, into silicon. It is widely recognized that silicon semiconductor can respond to visible light. Silicon photodetector can thus detect merely the light with wavelengths of visible light and near IR. The effect of Pt on photocurrent of a metal-semiconductor-metal (MSM) photodetector was investigated. The undoped and Pt-doped silicon photodetectors in this experiment were fabricated to test the current characteristics. It was found that Pt-doped photodetectors can respond to the light wavelength of 365 nm. The energy bandgap (Eg), a parameter related to the optical response of semiconductor, of Pt-doped silicon was obtained by extracting from Arrhenius plot of generation current of silicon p-n junction. The result was shown that Eg of Pt-doped silicon is increased with the introduction of Pt. Eg of silicon is typically 1.12 eV; however, the Eg in this study is approximated at 1.7 eV. © 2013 American Scientific Publishers All rights reserved.