We achieved <i>p-</i>(Zn,Mg)O by doping with phosphorous and the conduction type was confirmed by capacitance-voltage properties of metal/insulator/<i>p-</i>(Zn,Mg)O:P diode structures as well as Hall measurements. The <i>p-</i>(Zn,Mg)O:P/n-ZnO junction was grown by pulsed laser deposition on bulk ZnO doped with Sn. Without post-growth annealing, the phosphorous-doped ZnMgO showed <i>p</i>-type conductivity (hole density ~10<sup>16</sup> cm<sup>-3</sup>, mobility ~6 cm<sup>2</sup>V<sup>-1</sup>s<sup>-1</sup>) in the as-grown state. The metal contacts in top-to-bottom <i>p-n</i> junctions were made with Ni/Au as the <i>p-</i>ohmic and Ti/Au as the backside <i>n-</i>ohmic contact. The <i>p-</i>contacts showed improved characteristics after annealing up to 350 - 400 °C, but the <i>n-</i>contacts were ohmic as-deposited. The simple, low temperature growth (≤500 °C) and processing sequence (≤400 °C) shows the promise of ZnO for applications such as low-cost UV light emitters and transparent electronics.