Dual energy converting nano-phosphors: upconversion luminescence and X-ray excited scintillation from a single composition of lanthanide-doped yttrium oxideElectronic supplementary information (ESI) available: Synthetic procedures, XRD, SEM, TEM, and power-dependent UCL data. See DOI: 10.1039/c2dt31616a

We report an upconverting nanomaterial composition, [Y 2 O 3 ; Yb (2%), Er (1%)], that converts both X-ray and high-fluence NIR irradiation to visible light. This composition is compared to a higher Yb 3+ doped composition, [Y 2 O 3 ; Yb (10%), Er (1%)], that displays diminished visible X-ray scintillation, but shows enhanced red wavelength centered upconversion emission. These nanocrystals have been characterized by TEM, X-ray diffraction, power-dependent upconversion luminescence, and X-ray scintillation spectroscopy. We further demonstrate that lithium ion doping of the [Y 2 O 3 ; Yb (2%), Er (1%)] nanoscale composition leads to enhanced X-ray and NIR excited emission intensities through the production of nanoparticles that feature slightly enhanced sizes and increased crystallinity. We report an upconverting nanomaterial composition, [Y 2 O 3 ; Yb (2%), Er (1%)], that converts both X-ray and high-fluence NIR irradiation to visible light.