Fig. 9. ErIII-centred NIR PL properties of 1a, 1a_des and 1b. (a) PL spectra of 1a and 1a_des at room temperature. (b) Low-temperature (77 K) spectrum of 1a_des with multiple Gaussian fit. Vertical bars represent the radiative transitions from the 4I13/2 lowest level to the ground (4I15/2) multiplet levels estimated from theoretical calculations. (c) PL decay transients for 1a and 1a_des at room temperature and at 77 K. Biexponential decay fits and amplitude-averaged lifetimes are shown as well. (d)–(f) Same as (a)–(c) but for 1b.
