Dy3+ doped Y2MoO6 nanopowders for white light emission: Spectroscopic and transport properties for optoelectronic and energy harvesting applications

In this communication, we report the white light emitting Dy3+ ions doped Y2MoO6 (YMO) nanopowders (NPs) prepared via green combustion synthesis route by utilizing the Aloe vera (AV) gel as surfactant. For the convenient to the readers, we represent Y2MoO6:Dy3+ as YMOD. The cubic structure of the YMOD is confirmed by the results of powder X-ray diffraction (PXRD). The energy band gap values are studied by diffuse reflectance spectra (DRS) plots and the observed values are found to be in the range of 3.33-3.43 eV. The block-like structures of the fabricated nanopowders is analyzed by means of scanning electron microscope (SEM) images. Transmission electron microscope (TEM) images are castoff to evaluate the particle size of the prepared powders. The crystallinity and interplanar spacing are analyzed by means of selected area diffraction (SAED) and high-resolution TEM (HRTEM) images respectively. In order to study the luminescence behaviour of the fabricated powders, the photoluminescence spectra are recorded in the range of 400-675 nm under 386 nm excitation wavelength. There are three prominent peaks positioned at 480, 575 and 637 nm which are corresponding to the F-4(9/2) -> H-6(15/2), (13/2) and 11/2 respectively. The direct current conductivity is studied in the temperature range from 30 to 400 degrees C. The DC conductivity of NPs increases with increase in temperature. The color emission of the fabricated powders is studied by means of color diagrams namely, CIE and CCT. It is noticed from the color diagrams that, the emission color lies in the bright white region (0.33, 0.33) which is a characteristic emission of the Dy3+ doped powders. The obtained CCT value (5426 K) indicates that the prepared powders can be effectively utilized for cool LED sources in the indoor lighting applications. The average color purity (CP) values are found to be 80%. The quantum efficiency of the prepared nanopowders is found to be similar to 86.82%. The above findings substantiate the ability of YMO: Dy3+ phosphor to be used in photovoltaic and display device applications.