面向柔性光电晶体管的CH3NH3SnX3薄膜构筑、卤素替位掺杂及双极性载流子输运机制研究

Flexible photoelectric thin-film transistors with advantages of light weight, low cost and flexibility, is the core of next-generation wearable electronics devices. This project aims to use flexible material as substrate layers, controllably fabricates Sn-based perovskite semiconductor channel layer with good crystallinity, high density and excellent interface matching by using atomic layer deposition technology, to improve the carrier transport capacity of perovskite and interlayers, and control the light response and stability characteristics by halogen substitutional doping, further to obtain the flexible phototransistor with high hole-electron mobility, high light response and stable property, finally realize the photoelectric dual modulation of phototransistors. The effect of atomic layer deposition parameters on the phase composition, electrical performance and interfaces of layers for the thin films in transistor structure have been investigated. The internal relationship between halogen substitutional doping with the band structure regulation, crystal evolution and defect state properties of Sn-based perovskite semiconductor material have been investigated by using the neutron diffraction technique. The effect of structural, optical and electrical characteristics of Sn-based perovskite semiconductor on its carrier migration and light response characteristics of phototransistor have been investigated. The relationship mode of light field-electrical field-carrier transport have been established, and the ambipolar carrier transport mechanism of Sn-based perovskite semiconductor have been revealed.

柔性光电薄膜晶体管具有质量轻、成本低和柔韧性好等优点，是下一代可穿戴电子设备的核心器件。本项目以柔性材料为基底，采用原子层沉积技术可控制备结晶度好、致密度高、界面匹配性优良的锡基钙钛矿半导体沟道层，以提升钙钛矿薄膜及层间的载流子传输能力，并通过卤族元素替位掺杂调控其光响应特性及环境稳定性，从而得到空穴和电子迁移率均高、光响应度大且性能稳定的柔性光电晶体管，实现高效稳定的光电协同调控。系统研究原子层沉积工艺参数对所制备的晶体管各层薄膜相组成、电学性能以及层间界面态等影响规律。运用中子衍射技术，研究卤素替位掺杂与锡基钙钛矿半导体的能带结构调控、晶型演变以及缺陷态性质之间的内在联系，探讨钙钛矿半导体薄膜的结构组成及光电性质对晶体管载流子迁移性能及光响应特性的影响规律，建立“光场-电场-载流子输运”三者之间的关系模型，揭示钙钛矿半导体双极性的载流子输运机制。

项目系统研究了光电性能优异的新型沟道层材料和通过ALD技术实现晶体管电极层、HfO2薄膜为介电绝缘层以及封装层的一体化制备。具体包括甲脒基（FAPbI3）、锡基钙钛矿薄膜和碳材料改性钙钛矿材料工艺参数优化，以及原子层沉积工艺参数对晶体管各层薄膜相组成、能带结构、电学性能以及层间界面态等影响规律。运用中子衍射技术，瞬态荧光光谱结合理论计算等手段研究材料微观结构和性能演变规律，探讨了钙钛矿层形貌、结晶性、晶型演变和缺陷态性质与光电性能之间的内在联系，揭示钙钛矿膜层界面结构特性对光-电转换性能的影响规律和电荷传输机理；研究了FAPbI3和HfO2构成的钙钛矿光电晶体管自诱导钝化对器件性能的影响，通过对沟道层、电极层和绝缘层各层材料、成分及厚度进行有效控制，结构设计、材料优化和界面调控，探讨钙钛矿半导体薄膜的光电特性对晶体管载流子迁移性能及光响应特性的影响机制，为钙钛矿晶体管研制、选材、及光电性能优化科学决策提供理论支持。本项目在Journal of Physical Chemistry C, Industrial & Engineering Chemistry Research，ACS Applied Materials and Interfaces等杂志发表SCI论文12篇，获得国家发明专利6项，顺利完成，达到预期目标。项目负责人获得了黑龙江省优秀青年人才称号，相关技术成果在风云四号气象卫星上成功应用，并获得省部级一等奖1项。