Robust and Flexible Random Lasers Using Perovskite Quantum Dots Coated Nickel Foam for Speckle‐Free Laser Imaging

Abstract The advantage of using flexible metallic structures as the substrate of flexible lasers over plastic materials is its strong mechanical strength and high thermal conductivity. Here, it is proposed to deposit CsPbBr 3 perovskite quantum dots onto Ni porous foam for the realization of flexible lasers. Under two‐photon 800 nm excitation at room temperature, incoherent random lasing emission is observed at ≈537 nm. By external deformation of the Ni porous foam, incoherent random lasing can be tuned to amplified spontaneous emission as well as the corresponding lasing threshold be controlled. More importantly, it is demonstrated that the laser is robust to intensive bending (>1000 bending cycles) with minimum effect on the lasing intensity. This flexible laser is also shown to be an ideal light source to produce a “speckle” free micro‐image.