Erasable laser 3D printing of stable perovskite CsPbBr₃ nanocrystals in fluorophosphate glass

In this work, perovskite CsPbBr₃ nanocrystals (NCs) were grown using a femtosecond laser (fs) in a transparent fluorophosphate (FP) glass matrix without damage to the material. TEM images showed the in situ formation of CsPbBr₃ quantum dots (QDs) with sizes of 3-4 nm in the glass matrix after fs laser irradiation. Additional low-temperature treatment leads to the growth of NCs (12 nm) and the appearance of luminescence due to the annealing of defects caused by the capture of photoelectrons by the glass matrix. The effects of writing conditions (pulse power, repetition rate, and recording speed) on luminescence were analyzed. The long-term relaxation of the electronic subsystem in CsPbBr₃ NCs after high-energy fs pulses was recorded. Luminescence spectra at cryogenic temperatures (10 K) and TEM images showed a two-mode size distribution of NCs. The erasure-recovery process of the record was examined, and it was found that the luminescence disappeared when the luminescent NCs were exposed to lower-energy fs pulses. Full recovery of luminescence of Ns occurred during low-temperature annealing at 100-300 °C. Such recording and erasure processes can be repeated for many cycles without changing the luminescence parameters. The stability of the luminescence parameters of NCs in the glass matrix in response to external influences and temperature makes them promising in such fields as high-capacity optical data storage and information encryption.