Highly compact and smooth all-inorganic perovskite films for low threshold amplified spontaneous emission from additive-assisted solution processing

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2019, Vol.7 (48), p.1535-15356
• Main Authors: Li, Jing, Zhou, Wei, Jiang, Li, Fang, Zhishan, Yang, Zhaoliang, Lin, Chen, Xu, Xiaoli, Ye, Zhizhen, Zhu, Haiming, He, Haiping
• Format: Article
• Language: English
• Subjects: Amplification; Augers; Coherent light; Light emission; Morphology; Perovskites; Pinholes; Spontaneous emission; X ray photoelectron spectroscopy
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/c9tc05090f

Solution-processed perovskites have shown great potential for coherent light emission, i.e. lasing, owing to their high optical gain and tunable gain profile over a broad range. For all-inorganic perovskite films, however, morphology-control is still a challenge to suppress the optical loss. Herein, we report a facile one-step solution-based approach to grow CsPbX 3 (X = Br and I) perovskite films with a pinhole-free and ultra-smooth surface, by incorporating long-chain octylammonium halide as an additive. The addition of octylammonium halide hardly affects the Auger recombination rate under high excitation. The optimal perovskite films exhibit roughness less than 2 nm and low scattering loss. These merits facilitate wavelength tunable amplified spontaneous emission (ASE) with a low threshold of 14.9 μJ cm −2 and a high net gain coefficient of 380 cm −1 . Adding octylammonium halide into perovskite precursors leads to highly compact and ultra-smooth CsPbX 3 films with low threshold amplified spontaneous emission.