Random lasing in cesium lead iodide (CsPbI) thin films with no surface passivation.

We report the CsPbI random lasing at room temperature fabricated by a chemical deposition method. The CsPbI thin films with high crystalline quality have intense PL emission and easily achieve the lasing behavior with the Q-factor value over 7000. The lasing behavior of CsPbI thin films can be classified as random lasing by measuring lasing spectra at different collective angles. The fast Fourier transform analysis of the lasing spectra is employed to determine the effective cavity length. Most important of all, the lasing stability investigation shows the prolonged lasing stability over 4.8 X 10 laser shots in air.