Characterizations of phosphorus doped ZnO multi-layer thin films to control carrier concentration

Phosphorus doped ZnO multilayer (ZnO:P) thin films were deposited in various oxygen partial pressures on (001) sapphire substrates by pulsed laser deposition (PLD). The phosphorus doped ZnO multilayer was deposited with a phosphorus doped ZnO layer and two pure ZnO layers on a sapphire substrate at various oxygen partial pressures. The ZnO/ZnO:P/ZnO multilayer thin films were post-annealed at 400 ∘C for 40 min. The top ZnO layer plays an important role to encapsulate phosphorus atoms in the ZnO:P layer activated by a post-annealing process. The carrier concentration could be controlled by using a ZnO multilayer structure. The structural, electrical and optical properties of the ZnO multilayered thin films have been investigated by X-ray diffraction (XRD), Hall measurements and photoluminescence (PL).