Hedgehog ZnO/Ag heterostructure: an environment-friendly rare earth free potential material for cold-white light emission with high quantum yield

Solid-state white light emission from environment-friendly, highly stable hedgehog ZnO/Ag heterostructure has been observed for first time from a combined effect of tunability of emission centers and charge transfer. The heterostructure has been synthesized via a facile low-temperature hydrothermal route and characterized using X-ray diffractometer, scanning electron microscope and transmission electron microscope. The interaction between ZnO and Ag can be confirmed from the appearance of few new multi-phonon Raman peaks. Steady-state photoluminescence spectrum reveals multiple emissions (413, 453, 546, 605 and 667 nm) from virgin hedgehog ZnO at an excitation wavelength of 325 nm. Tuneability of radiative and non-radiative emission of ZnO which is the primary mechanism for white light emission (CIE coordinate: 0.35, 0.32) has been briefly investigated by time-correlated single-photon spectroscopy. Biocompatible as well cost-effectivity depicts that the as-prepared heterostructure would be a promising solid-state white light-emitting phosphor material for long-term use. Graphical abstract