Pulsed laser deposition of ZnO in N2O atmosphere

Abstract

The contribution deals with ZnO thin layers doped by nitrogen which were prepared by pulsed laser deposition in N2O ambient atmosphere. Our approach is based on ablation of undoped ZnO target in active atmosphere containing N2O gas without any supporting excitation equipment in parallel. Ablation of ZnO target was performed at different pressures (1–32 Pa) of N2O ambient atmosphere by pulsed Nd:YAG laser (at 355 nm). Layers of ZnO were grown on different substrates (Si, sapphire, fused silica) and their properties were investigated by various analytical methods: scanning electron microscopy (SEM), secondary ion mass spectroscopy (SIMS), X-ray diffraction (XRD), and optical transmission spectroscopy. The results confirmed incorporation of nitrogen into ZnO layers and its concentration was pressure dependent. According to SIMS analysis, there is a certain pressure level (above 10 Pa) when the presence of N becomes negligible. Transmittance spectra showed increasing of the optical band gap (Eg) according to the pressure of N2O.