Figure 4.

(a) TA spectra (in the 420–550 nm range) of the Cu₂Ag₂I₄:Bi film excited at 400 nm. (b) The decay curves of PIA peaks at 440 and 480 nm. The inset highlights the slow components (which correspond to radiative recombination) of the two decay curves. (c) The decay curves of PIA peaks at 440 and 480 nm up to 10 ps. (d) Schematic of the adiabatic potential energy curves of the ground state (GS), free carrier (FE), free exciton (FE), and dual trapped emissive excited states in a configuration space. The vertical dashed arrows and the horizontal dashed arrow indicate the radiative (emission) and nonradiative processes, respectively, under 400 nm photo excitation.