Rietveld Refinement, Morphology, and Optical and Photoluminescence Properties of a β‑Ag1.94Cu0.06MoO4 Solid Solution

Corner-truncated cubic β-Ag1.94Cu0.06MoO4 microcrystals were synthesized using the hydrothermal method. These were investigated by X-ray diffraction, confirming obtention of the spinel structure Fd3̅m. Through Raman spectroscopy are confirmed all modes for the point group of O h 7. The E gap shows a decrease of the band gap from 3.20 to 3.07 eV, with reduction of the conduction band occurring from −0.20 eV (β-Ag2MoO4) to −0.13 eV (β-Ag1.94Cu0.06MoO4), suggesting a p-type behavior for the Cu2+ ion. The field-emission scanning electron microscopy images confirm the morphological changes for β-Ag2MoO4, where potato-like microcrystals were found. Meanwhile, corner-truncated cubic microcrystals for β-Ag1.94Cu0.06MoO4. The photoluminescence (PL) spectrum confirms the increase in the PL emission for β-Ag1.94Cu0.06MoO4, with suppression of the deep defects occurring in the structure caused by oxygen and silver atoms. In contrast, the green region is intensified because of distortions of the Ag–O and Mo–O bonds. Therefore, the β-Ag1.94Cu0.06MoO4 solid solution has PL emission with CCT (4510 K) and CIE coordinates (x = 0.372 and y = 0.433), which could be interesting properties for applications as light-emitting diodes.