面向图像传感的超高速自驱动柔性钙钛矿光电探测器可控制备研究

The development of perovskite photodetectors is an important way to achieve ultrafast flexible photodetection, which brings new opportunities for the development of high-speed flexible image sensing technology. But the existing flexible perovskite photodetectors are difficult to meet the functional requirements of ultrafast photoresponse and self-powered stable photodetection at the same time, thus the preparation of ultrafast flexible photodetectors for image sensing still face enormous challenges. This project intends to deeply study the physical properties of functional materials and the photoresponse process of devices, reveals the transport mechanism of photogenerated carriers under multi-field effects of light, electricity and heat, and uncovers the main parameter control strategy of low temperature process and its influence on device performance. This project also intends to use band-gap regulation, ion doping, interfacial modification and so on to passivate interfacial defects, solving the problems of poor crystallinity and many defects of functional layers caused by the low temperature process and flexible substrates, establishing performance control methods and realizing the controllable preparation of ultrafast self-powered flexible perovskite photodetectors. Furthermore, this proposal will conduct the design, preparation, packaging and integration of high-density pixel array, to explore the application of perovskite photodetectors for high-speed and high resolution image sensing, laying foundation for the promotion and popularization of novel photodetecting and image sensing devices.

钙钛矿光电探测器的研发是实现超高速柔性光探测的重要途径，为高速柔性图像传感技术的发展带来了新契机，但现有柔性钙钛矿光电探测器还难以同时满足超高速光响应、自驱动稳定光探测等功能需求，面向图像传感的超高速柔性光探测器件的制备研究仍面临巨大挑战。本项目拟深入研究功能材料物理特性及器件光电响应过程，揭示钙钛矿光电探测器光、电、热多场作用下光生载流子输运机制，探索低温工艺环节主要参数控制策略及其对器件性能的影响规律，通过带隙调控、离子掺杂、界面修饰等方式钝化界面缺陷，解决功能材料低温下结晶性差、柔性基底上成膜缺陷多的问题，进而建立性能调控方法，实现超高速自驱动柔性钙钛矿光电探测器的可控制备。进一步开展高密度像素单元阵列设计、制备、封装与集成，探索钙钛矿光电探测器高速高分辨图像传感应用，为新型光探测与图像传感器件的应用和推广奠定基础。

钙钛矿光电探测器的研发是实现超高速光探测的重要途径，为高速图像传感技术的发展带来了新契机，但现有钙钛矿光电探测器还难以同时满足超高速光响应、自驱动稳定光探测等功能需求，面向图像传感的超高速柔性光探测器件的制备研究仍面临巨大挑战。本项目深入研究功能材料物理特性及器件光电响应过程，揭示钙钛矿光电探测器多场作用下光生载流子输运机制，探索低温工艺环节主要参数控制策略及其对器件性能的影响规律，通过带隙调控、离子掺杂、界面修饰等方式钝化界面缺陷，解决功能材料低温下结晶性差、成膜缺陷多的问题，进而建立性能调控方法，实现超高速自驱动钙钛矿光电探测器的可控制备。进一步开展高密度像素单元阵列设计、制备、封装与集成，探索钙钛矿光电探测器高速高分辨图像传感应用。具体创新为：1）提出了一种钙钛矿Cu离子P型掺杂策略，显著提升了钙钛矿光电探测器的光探测性能，Cu离子掺杂有利于在钙钛矿与电子传输层界面处形成P-N节，进而促进载流子传输、钝化缺陷、减少电荷累积并减少光生载流子复合。优化后的器件获得了0.37AW-1的最高响应度，1.06×1012Jones的探测率，超过101dB的线性动态范围以及接近5μs的快速响应。进一步搭建了可见光通讯系统，成功用于字符与音频信号准确传输。2）开发了CsPbBr3、Cs2AgBiBr6无机宽禁带钙钛矿光电探测器全气相制备方法，器件优化后在0 V偏压下光响应时间低至0.96μs，开/关比达1.17×106，响应度达0.40A/W，探测率为5.22×1012 Jones，并呈现出良好的线性响应性和高频光响应性。进一步，构建了625像素图像传感器原型器件，呈现出良好图像识别与还原能力。3）首次公开了CsPbCl3宽禁带钙钛矿薄膜光电特性数据，提出了CsPbCl3光电子器件设计优化准则。器件开关比、响应度以及探测率分别可达1.08×106、248mA·W-1与2.04×1013Jones。进一步设计了1024像素CsPbCl3紫外成像探测芯片版图，像素敏感面积7*7mm，特征尺寸2μm，密度达100DPI，开发了紫外成像探测芯片MEMS工艺规程，提供了宽禁带半导体材料与集成电路后端集成方法，实现了紫外成像探测功能演示。本项目研究成果有力促进了钙钛矿光探测技术的发展及其在光通信、紫外探测、图像传感等领域的应用和推广。