A chemical route to fabricate Lu2Si2O7:Ce3+ micro-column structured films

Lu2Si2O7 (LPS):Ce3+ micro-column structured films have been prepared on silicon substrate by a chemical method which combines Si nanowire array wafers with dip-coating method. In the processing, the Si nanowire array wafers are obtained via a metal-assisted chemical etching route on single-crystal silicon (1 0 0) substrate at first step. The produced Si nanowire array wafers not only serve as guide-templates for the fabrication of LPS:Ce3+ films in a columnar fashion, but also provide Si sources for further reacting with lutetium sources at high temperatures to form LPS:Ce3+ micro-column structured films. XRD analysis indicates that as-prepared films are crystallized into a monoclinic Lu2Si2O7 phase along with an amorphous silicon oxide phase, and the latter phase ascribes to the oxidation of Si nanowire arrays. The as-prepared LPS:Ce3+ films exhibit a columnar-array structure and a uniform morphology according to SEM and TEM observations. The UV photoluminescence spectra illustrate the characteristic excitation and emission spectrum of Ce3+ ions in the host of LPS. X-ray induced emission spectrum reveals a similar shape with UV excited emission spectrum peaking at 378 nm. Furthermore, the LPS:Ce3+ micro-column structured films present a fast decay time of about 3425 ns. These experiments have demonstrated that the film technique thus developed is possible to fabricate column-like luminescent films of large scale with low cost.