Phosphorus-Doped p-Type ZnO Nanorods and ZnO Nanorod p−n Homojunction LED Fabricated by Hydrothermal Method

Abstract

Phosphorus-doped ZnO nanorods and ZnO nanorod homojunctions were prepared by a hydrothermal method. The structural and photoluminescent (PL) characterizations showed the P atoms doped into the ZnO crystal lattice. In low-temperature PL spectra the emission peaks located at 3.310 and 3.241 eV were observed, which could be attributed to a conduction band to the phosphorus-related acceptor transition and a donor−acceptor pair transition, respectively. ZnO homojunctions were synthesized by P-doped ZnO nanorods grown on undoped ZnO nanorods. The current−voltage (I−V) measurement based on the ZnO nanorod p−n homojunctions showed a typical semiconductor rectification characteristic with a turn-on voltage of about 3.14 V, which meant the conductivity of the P-doped ZnO nanorod might be a p-type conductivity. The electroluminescence was observed at room temperature for this homojunction, which contained a violet-blue emission and a broad visible band emission.