pn-junction rectifiers based on p-ZnO and n-ZnO nanoparticles

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.