Photoluminescence Enhancement of Titanate Nanotubes by Insertion of Rare Earth Ions in Their Interlayer Spaces

Figure 4

Temperature-dependent PL spectra: (a) Na-TiNts; (b) Nd-TiNts; (c) Pr-TiNts; (d) Er-TiNts; and (e) Yb-TiNts.

(a)

(b)

(c)

(d)

(e)