Figure 2.

Light-induced phase separation of CsPbI₂Br PNCs and thin films continuously excited by CW light at 405 nm with a laser power density of 3180 W cm^–2 during 0, 10, 20, 30, 40, and 50 min illuminations. Evolution of PL for (a) CsPbI₂Br PNCs and (b) CsPbI₂Br thin films. (c and d) PL spectra for the initial, light-induced, and dark recovery states of the PNCs and thin films, respectively. The initial spectrum is represented by the dark green line, and the spectrum after illumination for 50 min by the brown line. The turquoise line illustrates the spectrum after illumination for 4 h and the subsequent dark recovery.