Liu Xiaohong, Xu Caixia, Zhao Hongquan
Chongqing University, Shapingba, Chongqing 400044, China.
Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
Nanomaterials (Basel). 2023 May 30;13(11):1761. doi: 10.3390/nano13111761.
Herein, titanium-dioxide-decorated organic formamidinium lead bromide perovskite thin films grown by the one-step spin-coating method are studied. TiO nanoparticles are widespread in FAPbBr thin films, which changes the optical properties of the perovskite thin films effectively. Obvious reductions in the absorption and enhancements in the intensity of the photoluminescence spectra are observed. Over 6 nm, a blueshift of the photoluminescence emission peaks is observed due to 5.0 mg/mL TiO nanoparticle decoration in the thin films, which originates from the variation in the grain sizes of the perovskite thin films. Light intensity redistributions in perovskite thin films are measured by using a home-built confocal microscope, and the multiple scattering and weak localization of light are analyzed based on the scattering center of TiO nanoparticle clusters. Furthermore, random lasing emission with sharp emission peaks is achieved in the scattering perovskite thin films with a full width at the half maximum of 2.1 nm. The multiple scattering of light, the random reflection and reabsorption of light, and the coherent interaction of light within the TiO nanoparticle clusters play important roles in random lasing. This work could be used to improve the efficiency of photoluminescence and random lasing emissions, and it is promising in high-performance optoelectrical devices.
在此，研究了通过一步旋涂法生长的二氧化钛修饰的有机甲脒铅溴化物钙钛矿薄膜。TiO纳米颗粒广泛存在于FAPbBr薄膜中，有效地改变了钙钛矿薄膜的光学性质。观察到吸收明显降低，光致发光光谱强度增强。由于薄膜中5.0 mg/mL的TiO纳米颗粒修饰，观察到光致发光发射峰发生了超过6 nm的蓝移，这源于钙钛矿薄膜晶粒尺寸的变化。使用自制的共聚焦显微镜测量钙钛矿薄膜中的光强重新分布，并基于TiO纳米颗粒簇的散射中心分析光的多次散射和弱局域化。此外，在半高宽为2.1 nm的散射钙钛矿薄膜中实现了具有尖锐发射峰的随机激光发射。光的多次散射、光的随机反射和再吸收以及TiO纳米颗粒簇内光的相干相互作用在随机激光中起重要作用。这项工作可用于提高光致发光和随机激光发射的效率，在高性能光电器件方面具有前景。
