二维黑磷材料的化学修饰及非线性光学性质研究

As a recently discovered two-dimensional semiconductor, black phosphorus (BP) exhibits a tunable band-gap determined by the number of layers from 0.3 eV (bulk) to 2.0 eV (single layer). This material is expected to greatly widen the optical response of two-dimensional materials, but faces challenges for mass production due to the unstability in the air. Because of the high reactivity of phosphorus atoms and larger specific surface area of BP, this project focuses on its surface modification. We plan to modify the BP with organic molecules and/or gold nanoparticles in order to realize the following goals: (1) improving the stability of the BP by surface modification, (2) using the local surface plasmon resonance effect of gold nanoparticles to control the nonlinear optical properties of BP, (3) preparing the nonlinear optical devices of BP composites with superior performance, (4) revealing the mechanism between the modified layer and BP, as well as the connection with macroscopic properties. This study has guiding significance for the development of new two-dimensional nonlinear optical devices responding in broadband especially in mid-infrared spectrum.

二维黑磷作为近年来发现的一种窄带隙半导体材料，具有随着原子层数减少而带隙增加的特性，带隙范围为0.3eV-2.0eV。该材料的出现大大地拓宽了二维材料的光学响应范围，但是其在空气中很不稳定，不利于大规模制备。因此本项目针对磷原子的高反应活性及较大的比表面积，拟对其表面进行特异性修饰有机分子和金纳米粒子，期望达到：（1）通过表面修饰的方法提高黑磷的稳定性；（2）利用金纳米颗粒的局域表面等离子体共振效应调控黑磷的非线性光学性质；（3）制备性能优越的黑磷复合物非线性光学器件；（4）阐释修饰层-黑磷之间的作用机理以及与宏观性能之间的关联。该研究对宽波段尤其是中红外光区响应的新型二维非线性光学器件的开发具有指导意义。

二维黑磷作为近年来发现的一种具有良好的光学性能的半导体材料，呈现出随着原子层数减少而带隙增加的特性，带隙范围为0.3eV-2.0eV。由于该材料价格较为昂贵，因此我们选取和黑磷性质相似的锑烯作为研究对象，本项目主要研究了锑烯的制备及光电性能：（1）报道了利用离子液辅助剥离制备锑烯的方法，该方法制备的锑烯尺寸较为均匀；（2）把制备的锑烯量子片掺入有机太阳能电池的活性层中，其光电转换效率可以提升25%；（3）锑烯量子片可以修饰到有机太阳能电池的空穴提取层CuSCN表面，通过钝化CuSCN的缺陷可以有效提高电池效率；（4）锑烯量子片掺杂到PEDOT:PSS中，可以将其功函数从-5.2eV调至-4.9eV。锑烯掺杂的PEDOT:PSS作为Ir(ppy)3基OLEDs的空穴传输层，其开路电压可低至3.0V。（5）通过开孔Z-扫描研究了锑烯量子片的非线性光学性能，其在532nm和1064nm激光照射下均具有良好的光限幅响应。该研究对新型二维非线性光学器件以及光电器件的研究具有重要的指导意义。