超宽带近红外发光铋掺杂半导体与薄膜的可控制备、结构及光电性质研究

Broadband optical gain media in the near-infrared (NIR) spectral range have great potential in the field of information processing. Bismuth doped crystals and films have attracted extensive attention in recent years owing to their broadband NIR emission feature. However, up till now researchers in this domain have never realized electroluminescence using these media, which greatly hinders their broad applications. To realize electroluminescence from bismuth doped materials, it is required to solve the following two critical scientific and technological issues: 1) obtain bismuth doped NIR emitting semiconductors, and then study their structures and luminescence mechanisms; 2) obtain bismuth doped polycrystalline films with excellent optoelectronic properties by using a simple fabrication approach, and then determine the key experimental parameters that affect the film structures, morphologies, and optoelectronic properties. In this project, bismuth doped direct bandgap semiconducting CH3NH3PbI3 will be studied thoroughly based on the investigation of their fabrication methods, structures, and optical properties, and then the emphasis will be laid on the preparation of bismuth doped CH3NH3PbI3 semiconducting films with excellent optoelectronic properties, followed by the characterization of their structures, morphologies, and optoelectronic properties. This research will provide theoretical and experimental data for the development of bismuth doped NIR luminescent materials and pave the way for the application of this type of material in the area of electroluminescent devices. Therefore, this study possesses important scientific and technological values.

近红外波段宽带增益介质在信息处理方面有着广阔的应用前景，铋掺杂晶体及薄膜由于可实现超宽带红外发光而备受关注与重视，但截至目前以上材料难以实现电致发光，严重阻碍了其广泛应用。要实现该类材料的电致发光，该领域亟需解决两个关键科学与技术问题：1）获得近红外发光的铋掺杂半导体材料，明确材料结构及发光机理；2）获得成膜工艺简单、具有良好光电综合性能的铋掺杂半导体晶体薄膜，明确影响薄膜结构、形貌及光电性能的关键因素。本项目提出以铋掺杂甲基氨基碘化铅直接带隙半导体为研究对象，对该类材料的可控制备、结构及光学性质进行系统的研究，在此基础上采用旋涂技术制备具有优良光电综合性能的铋掺杂甲基氨基碘化铅多晶薄膜并表征其结构、形貌及光电性质。本研究将为推动铋掺杂红外发光材料在电致发光器件领域的应用提供理论依据和科学的实验数据，具有重要的学术研究价值和实际应用意义。

近红外波段宽带增益介质在信息处理方面有着广阔的应用前景，铋掺杂晶体及薄膜由于可实现超宽带红外发光而备受关注与重视。本项目以铋掺杂甲基氨基碘化铅半导体为研究对象，对该类材料的可控制备、结构及光学性质进行了系统的研究，制备了具有优良发光效率的甲基氨基碘化铅多晶薄膜并系统表征其结构、形貌及光电性质，在此基础上实现了通讯波段电致超宽带发光和超宽带光放大。重要结果如下：1）率先提出“通讯波段发光的卤化物钙钛矿”这一研究设想，并实验观察到铋激活半导体中掺杂诱导红外发光中心的新现象，验证了铋掺杂诱导结构缺陷可以作为红外荧光活性中心，提出了合理解释该发光现象的极化子模型并获得了实验证实。2）在高质量铋激活钙钛矿制备技术上获得突破，实现了低成本旋涂技术制备通讯波段发光铋激活无空洞钙钛矿薄膜，实验上实现了固溶体结构渐变调控铋掺杂材料发光范围，首次实现了该类材料在通讯波段的电致发光及超宽带光学放大，其增益系数超过传统铋激活材料三个数量级。该研究的重要意义在于不仅加深了铋激活发光材料发光机理的认识，丰富了铋激活材料设计调控的方法，同时拓展了钙钛矿材料的运作波段，光通讯波段电致发光器件及光放大器的研究将极大的拓展钙钛矿材料的应用前景。