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

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2021-10, Vol.17 (39), p.e2103065-n/a
• Main Authors: Gao, Wei, Wang, Ting, Xu, Jiangtao, Zeng, Ping, Zhang, Wenfei, Yao, Yunduo, Chen, Changsheng, Li, Mingjie, Yu, Siu Fung
• Format: Article
• Language: English
• Subjects: Bending; flexible lasers; incoherent random lasing; Lasers; Lasing; Light sources; Luminous intensity; Metal foams; Nanotechnology; Ni porous foams; Nickel; perovskite quantum dots; Perovskites; Quantum dots; Robustness; Room temperature; Spontaneous emission; Substrates; Thermal conductivity; two‐photon excitation
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202103065

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 CsPbBr3 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. Metal foams can be used as the substrates of flexible random lasers due to their well‐controlled configuration. Herein, metal halide perovskites quantum dots are coated onto nickel foams to realize flexible random lasers with tunable lasing characteristics by the deformation of the 3D nickel foams. This flexible laser is a potential light source for application in speckle‐free laser imaging.