基于共轭聚合物/钙钛矿量子点复合体系的高性能近红外窄带光电探测器研究

Narrow-band photodetection in near-infared(NIR) region has great potential in a number of frontier technologies, such as LiDAR,NIR imaging, wearable devices and so on. Therefore, exploring novel NIR narrow-band photodetector with simple-structure, low-cost and large-scale fabrication is of great importance and applicable value. This project aims at high-efficient, low-cost NIR narrow-band photodetector, combining with photogating, it plans to construct the NIR narrow-band photodetection based on conjugated polymer/perovskite quantum dots. The main research includes: 1. Modulating the energy level of perovskite quantum dots by adjusting the composition and size effect, and then constructing the conjugated polymer/perovskite quantum dots composited active layer; 2. researching the influence of change in trap state on response speed as well as responsivity of device, in order to improve the gain-bandwidth product of the narrow-band photodetector; 3. According to the aforementioned result, develop the narrow-band photodetection in multi-region NIR vis ultra narrow-band conjugated polymer sensitization. This project can provide new materials and device structure for NIR narrow-band photodetection, and benefit for realizing flexible optoelectrical devices, integration of photodetection-imaging in NIR and so on.

近红外窄带光电探测在激光雷达、近红外成像、可穿戴电子设备等前沿技术领域具有广泛应用前景。因此,寻求器件结构简单、成本低廉且易于大面积制备的近红外窄带光电探测器具有十分重要的科学意义和应用价值。本项目以高性能、低成本近红外窄带探测技术为目标，拟通过发展共轭聚合物/钙钛矿量子点有源层，结合光诱导浮栅，构筑近红外窄带探测器件。主要研究内容包括：1、利用组分调控和尺寸效应精确调制钙钛矿量子点能带结构，构筑满足近红外窄带光电探测性能的共轭聚合物/钙钛矿量子点复合有源层；2、研究陷阱态结构变化对器件灵敏度和响应速度的规律性影响，进而提高探测器的增益带宽积；3、在前述研究的基础上，发展超窄带隙共轭聚合物敏化有源层，拓展探测器件在近红外多波段范围内的窄带响应。本项目开展可为近红外窄带光电探测技术提供新的材料体系和器件结构，为实现柔性光电器件、近红外探测-成像集成等奠定基础。

随着元宇宙、人工智能等新兴科技的快速发展，高性能光电探测器作为信息获取的重要途径成为了近年来信息技术领域备受关注的研究热点之一。本项目围绕卤素钙钛矿独特的半导体特性，分别发展了高倍增钙钛矿量子点/共轭聚合物光电探测器、卤素钙钛矿量子点/聚合物复合光学膜增强硅基光伏电池以及卤素钙钛矿异质单晶光电探测器。本项目的执行，揭示了不同能级结构的钙钛矿量子点作为光诱导浮栅对有机倍增光电探测器性能的调控机制，其最高增益超过3500%，最大比探测率可达1.3*1012 Jones；一步法制备了荧光量子产率高达95%的钙钛矿量子点复合光学膜，显著提高硅光伏电池在短波辐照区域里的外量子效率，使得其绝对光电转换效率可提升约1%；开发了卤素钙钛矿异质单晶的原位生长技术以及卤素钙钛矿单晶的异质集成技术，其中基于钙钛矿单晶/硅耦合的集成光电探测器在X射线至近红外的宽波段范围中均表现出优异的光电探测性能，其耦合强度可达340,000 N m−2，可见光波段比探测率最高为4.36*1012 Jones，X射线波段灵敏度为1060μC Gyair−1 cm−2，最低检测限为42.6 nGyair s−1，-3dB带宽为6350 Hz，线性动态范围为120 dB。本项目相关研究成果在ACS Appl. Mater. Interfaces、Nanophotonics 、Chem. Mater. 、Cryst. Growth Des.等学术期刊共发表学术论文8篇，申请中国发明专利3项，为设计与发展基于卤素钙钛矿材料的高性能光电探测器提供了可靠的理论基础和实践指导。