Application of porous silicon microcavity to enhance photoluminescence of ZnO/PS nanocomposites in UV light emission

This paper presents ZnO nanostructures deposited on porous silicon (PS) and porous silicon microcavity (PSM) substrates by sol-gel method. The effects of annealing temperature and mass ration of zinc acetate to PVA on microstructure, and optical properties of ZnO/PS and ZnO/PSM nanocomposites were systematically investigated by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy. The XRD analysis confirmed that the ZnO/PS nanocomposite preferred strongly to (002) phase orientation. The PL spectra showed that there was a sharp and highly intense UV emission peak located at about 400 nm when annealing temperature was 800 degrees C for 30 min and the mass ratio of zinc acetate to PVA was 4:1. The detail cross-section FESEM images of ZnO/PSM showed that ZnO nanoparticles uniformly penetrated into all PS layers and adhered to them very well. Furthermore, ZnO/PSM nanocomposites showed relatively stronger UV emissions at around 400 nm compared to the PL spectra of ZnO/PS nanocomposites, that means one-dimension phonic crystal PSM can enhance the PL intensity of ZnO. Such a method may provide an interesting way to develop a new type of UV optoelectronic devices. (C) 2016 Elsevier GmbH. All rights reserved.