Phosphors with ultraviolet (UV) mechanoluminescence (ML) $\mathrm{Sr}{\mathrm{Al}}_2{\mathrm{O}}_4:\mathrm{Ce}$ (SAOCe) and $\mathrm{Sr}{\mathrm{Al}}_2{\mathrm{O}}_4:\mathrm{Ce},\mathrm{Ho}$ (SAOHoCe) were reported in this letter. The results reveal that the ML emission band is located at $375\mathrm{nm}$ similar to photoluminescent (PL) peak, which indicates that ML is emitted from the same center of ${\mathrm{Ce}}^{3+}$ ions as PL. Furthermore, the addition of ${\mathrm{Ho}}^{3+}$ increases the UV ML intensity of SAOHoCe $(56\mathrm{nJ}∕\text{load}\text{cycle})$ considerably [approximately two orders of magnitude greater than that of SAOCe $(0.21\mathrm{nJ}∕\text{load}\text{cycle})$ ]. The formation of many shallow traps $({\mathrm{Ho}}^{3+}-{\mathrm{e}}^{-})$ may be responsible for this enhancement.

The nanostructured assembly of porphyrin and gold nano-particles exhibits distinct enhancement of photocurrents from porphyrin in the longer wavelength region, where the localized plasmon resonance was responsible.