Infrared to Visible Upconversion Photoluminescence from Nd-doped Yttria Ceramic for Optical Applications

Abstract

Upconversion photoluminescence (UCPL) attracts great attention in the field of optics and solid state lightening applications. Thus, in order to understand the underlying mechanisms of UCPL, this work reports on the spectral and kinetic properties of up and down conversion photoluminescence (PL) from Nd-doped Y2O3 ceramic. The energy transition levels and the possible excitation mechanisms are discussed. Nd-doped Y2O3 nanocrystals have been prepared via co-precipitation method then subjected to sintering process for ceramic production. The X-ray diffraction (XRD) and scanning electron microscope (SEM) measurements have been used to reveal the formation of nanocrystals and the crystal phase of the prepared Nd-doped Y2O3 powders. It is found that the PL down conversion (DCPL), from ceramic sample, demonstrates well-resolved narrow emission lines related to the near-infrared transitions in Nd ions, when excited by different UV–visible wavelengths. On the other side, a visible upconversion PL (UCPL) has been detected under excitation by a 1064-nm pulsed laser. In addition, the UCPL together with the photoluminescence excitation (PLE) results have been used to confirm the proposed energy levels for the upconversion process. Moreover, the excitation power dependence of the UCPL and time-resolved photoluminescence (TRPL) have been measured in order to determine the dominant excitation mechanism responsible for the upconversion. our findings suggest that the excited state absorption mechanism (ESA) is likely the possible mechanism of UCPL process in rare earth (Nd) single-doped Y2O3 ceramic.