p-n Junction Diode Fabricated From ZnO Nanorod Grown By Aqueous Solution Method

Abstract

The growth of n-type and p-type ZnO nanorods using aqueous solution method was introduced in this thesis. The n- and p- ZnO nanorods are single crystalline and vertically aligned on GaN substrate. The n-type ZnO nanorods was obtained either by unintentional hydrogen doping or doping with Ga. The p-type ZnO nanorods was obtained by doping with potassium. This work overcomes the difficulty that remains in p-type ZnO synthesizing to obtain stable p-type ZnO with relatively high carrier concentration, 2x10^17cm^-3, and high carrier mobility, 117cm^2/Vs. The p-type conductivity of ZnO nanorods was confirmed by fabrication of p-type ZnO nanorod/n-GaN film heterojunction LED and ZnO core-shell nanorod homojunction LED. These LEDs demonstrate rectifying I-V characteristics and electroluminescence spectra. The EL spectra of these LEDs contain an ultraviolet peak near band-edge of ZnO and a broad visible peak centered at 560nm.