高稳定的溴铅铯量子点制备及发光二极管应用

Preparation of Highly-stable CsPbBr_(3)Quantum Dots and Light Emitting Diode Application

通过合理设计钙钛矿量子点(Quantum Dots,QDs)的表面配体,采用在大气水氧暴露的环境中一步合成钙钛矿量子点的制备方法,以3-氨丙基三乙氧基硅烷为表面配体,采用热注入法直接制备二氧化硅包裹的溴铅铯量子点(CsPbBr_(3)@SiO_(2)QDs)核壳结构.研究反应时间对二氧化硅壳层厚度的影响,利用透射电子显微镜和X射线光电子能谱仪表征量子点核壳结构的形貌,分析材料的元素组成.利用光谱仪表征材料在水、氧、光照等环境下的发光光谱,分析和讨论光谱的时间稳定性.实验结果表明,反应时间为30 min时,可成功制备壳层均匀、形貌良好的CsPbBr_(3)@SiO_(2)QDs.得益于二氧化硅壳层的包裹和高分子膜的封装,量子点在刮涂成膜后,其光学薄膜仍保持优越的光致发光性能;在水氧环境下的稳定性得到了改善,置于水中180 d仍可保持较高的光致发光强度;进一步将量子点溶液应用于发光二极管器件,可实现较窄的发光峰和较高的光谱稳定性.

By reasonably designing and exploring the surface ligand of Quantum Dots(QDs),this work adopts a one-step synthesis of perovskite QDs in the atmospheric environment.Utilizing 3-aminopropyl triethoxysilane as surface ligands,the core-shell structures of silica coated CsPbBr_(3)QDs(CsPbBr_(3)@SiO_(2)QDs)were directly prepared by thermal injection method in the air.The effect of reaction time on the thickness of the silica shell was systematically studied,and the morphology and composition of core-shell QDs were characterized by transmission electron microscopy and X-ray photoelectron spectroscopy.The photoluminescence spectra were used to record the characteristics of light emission spectra under the environment of water,oxygen and lighting,and the time stability of spectra was analyzed and discussed.These results show that core-shell QDs with high-quality perovskite core and uniform silica shell were successfully prepared at a reaction time of 30 min.Benefitting from the coating of silica shell and organic supporting film,QDs optical film still maintained the high-efficiency photoluminescence,and its stability in water and oxygen environment had been greatly improved.The spectral peak and intensity of the optical film were even stable after 180 days.Furthermore,our core-shell perovskite QDs were applied in light emitting diode devices,showing bright light emissions with narrow full width at half maxima.