Native point defect modulated Cr3+-LaAlO3 as an in vitro excited contrast medium for in vivo near-infrared persistent deep-tissue bio-imaging.

Due to the synergistic effect of Cr3+ dopant levels and defect state, the luminescence intensity and decay time in LaAlO3 are remarkably enhanced, and the emission wavelength from deep-red (Cr3+ as the luminescent center) to NIR-II/III (defect states as the luminescent center) can be effectively tuned via an energy transfer process.