Photoluminescence properties of spark-processed CuO

This paper reports the preparation of photoluminescing porous CuO using spark discharge in ambient air. The photoluminescence (PL) characteristics of spark processed CuO (sp-CuO) have been studied at various temperatures. Further studies of scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) have been performed. Visible light emission with peaks at around 400 and 570 nm is obtained from CuO. In addition to the visible light emission peaks at around 400 and 570 nm of bulk CuO, the photoluminescence studies of sp-CuO at room temperature and low temperature reveal two additional emission peaks at around 470 and 505 nm. XPS studies show that the slightly higher binding energy shift (Cu) and a broader peak which indicates an increase of multiple oxidation state. The newly detected emission bands of sp-CuO compared to the bulk CuO is associated with defect states within the emission peaks of CuO.