Photoluminescence and<i>I</i>-<i>V</i>characteristics of a CdS-nanoparticles-porous-silicon heterojunction

Abstract

Chemically capped CdS nanoparticles are embedded in porous silicon (PS) by a dip coating method. Atomic force microscopy measurements reveal that the PS surface is covered with CdS nanoparticles forming well-defined rectangular blocks of nearly uniform size (200×200 nm2). Photoelectron spectroscopy and energy dispersive x-ray analysis confirm the presence of CdS in PS. Optical and electrical properties of the heterojunctions so-formed are investigated. Junction characteristics show that the composite so-formed exhibits very high forward current density (145 mA cm-2) and high reverse breakdown voltage (15 V).