全无机钙钛矿CsPbI3纳米线阵列的可控制备及其光探测性能研究

Development of photodetectors with high performance and integration is one of the main trends of light detection in the future. All inorganic perovskite CsPbI3 is ideal candidate for photodetectors owning to its merits of high carrier mobility and large absorption coefficient. Nanowires are excellent carrier for investigating photoelectric performances since they provide one-dimensional channel for the transport of electrons and holes. Assembling nanowires into arrays can improve the constructing efficiency and stability of devices, and promote the integration and functionality of devices as well. However, it is still difficult to fabricate CPbI3 nanowire arrays (NWAs) at present. Herein, we adopt a “separate electrodes” strategy based on electrospinning to realize controllable synthesis of microstructure of CPbI3 NWAs through changing the viscosity of precursor and heating temperature; and further investigate the impact of electrostatic interaction on the morphology of CPbI3 NWAs. Our aim is to control the parallelism, density, and direction of CPbI3 NWAs through “separate electrodes” strategy. We will further analysize and evaluate the photodetecting properties of the NWAs. The photoconductivity model of CsPbI3 NWAs will be built up through device simulation to explore the relationship between microstructure and photoelectric properties. This project will provide novel strategy for investigating the synthesis of CsPbI3 NWAs and is of great significance for the development and application of perovskites based photodetectors.

高性能、高集成度的光探测器是未来光探测发展的主要趋势之一。全无机钙钛矿CsPbI3具有载流子迁移率高、吸收系数大等优点，是构筑高性能光探测器的理想材料。纳米线能为载流子传输提供最直接的一维通道，是研究光电性能的良好载体；而将纳米线排列成阵列，可以提高器件制备效率及稳定性，有利于器件的集成化和功能化发展。目前，CsPbI3纳米线阵列的制备仍是难题。本项目拟采用“分离电极”的静电纺丝方法，可控制备CsPbI3纳米线阵列并研究其光探测性能。通过改变溶液粘度及后处理温度等条件，实现纳米线形貌及微观结构的调控；研究静电作用力对阵列形貌的影响规律，实现阵列平行性、密度和方向的调控。在此基础上，分析和评价CsPbI3纳米线阵列器件光探测性能；并借助器件模拟方法，探讨纳米线阵列微观结构对光探测性能的影响机理。本项目有望为CsPbI3纳米线阵列的制备提供新的思路，对实现钙钛矿材料的光电子应用具有重要意义。

申请人在全无机钙钛矿纳米材料的可控制备及其光电性能研究方面取得了以下成果：（1）构造限域空间控制CsPbI3钙钛矿纳米片的扩散和生长动力学过程，通过化学气相沉积方法可控制备超薄、高结晶性CsPbI3钙钛矿纳米片并研究其受激辐射激光性能；（2）通过调控溶液浓度及温度等条件实现钙钛矿纳米片材料的沉积速率及扩散速率的控制，成功制备少层厚度的Mn2+掺杂的CsPbCl3钙钛矿纳米片;（3）进一步扩展到亚毫米级无铅全无机Cs3Sb2Br9钙钛矿纳米片的制备及光探测性能研究。在Adv. Mater.，Nano Energy, Adv. Opt. Mater. 等SCI期刊发表论文6篇，其中第一作者论文3篇，申请获批华中科技大学材料成形与模具技术国家重点实验室开放课题1项。本项目旨在进一步理解CsPbI3钙钛矿纳米片生长机制，并应用于更多种类的全无机钙钛矿纳米材料的可控制备及光电性能研究。