Excellent Red Phosphors of Eu3+ Activated Double Perovskite Structured Series NaSrBi1-xEuxMoO6 (x = 0.0-0.24) Prepared by Citrate-Gel Method

Abstract

In this work, a double perovskite structured series was prepared by using simple citrate sol-gel method at 700 ºC for 5 h of sintering. The concentrated sample of x = 0.12 exhibits more intensity than all other concentration in their emission spectra for every series. Particle size, thickness of the particle, distance between particles and its surface morphology were identified by scanning electron microscopy. The size and distance between particles in each series lies in between the range of 1 μm-50 nm and 20-50 nm, respectively. Many voids with strong agglomerations were also observed. In addition, the absorption of light capacity for each series investigated through diffuse reflectance spectra method. All the samples of double perovskite structures exhibit a sharp cut-off of absorption light in the UV-visible regions of diffuse reflectance spectra. Predominantly, all the samples shows a very good charge transfer band in their excitation spectra that leads to more absorption of light correspondingly emits high intensity in emission spectra at 395, 464 and 545 nm. All the samples of every series emit main peaks in the range of 550-700 nm in their emission spectra. Out of all four main peaks, 614 nm peak represents the red phosphor with 5D0-7F2 transition in the emission spectra. The prepared double perovskite structure compound CRI coordinates were almost close to commercially available red phosphor i.e. Y2O2S(0.67,0.33) as per NTSC. Hence, the prepared red phosphors can be used in order to display devices, luminescent materials and WLEDs.