“…, opened new avenues in the fields of solid-state lighting, displays, lasers, sensors, and bio-medical imaging, among others. 1–5 The above-mentioned groups show broadband emission in the visible region due to O 2− –M x + (M x + = Ti 4+ , V 5+ , Nb 5+ , Ta 5+ , W 6+ , and Mo 6+ ) charge transfer bands that are associated with the respective metal–oxygen polyhedra. 6,12,32 These groups show negligible overlapping of their broadband absorption and emission in the visible region due to the minor visible photon reabsorption.…”