<i>pn</i>-Junction Rectifiers Based on <i>p</i>-ZnO and <i>n</i>-ZnO Nanoparticles

Abstract

We form pn -junctions by electrostatic binding of a p -type and an n -type ZnO nanoparticle. Current−voltage characteristics of pn -junctions are rectifying in nature. Individual components of the junction do not show any rectification. An np -junction, formed by reversing the binding sequence of the two types of nanoparticles, shows rectification in the reverse bias direction. By controlling the type of dopants in the ZnO nanoparticles, pn + (and n + p ) and nn + (and n + n ) junctions are formed that exhibit rectification. Current rectification in a junction between two nanoparticles shows that a depletion layer may have formed even in the quantum dot regime.