基于局域场调控的二维材料红外光电探测新机理及应用研究

In recent years, a series of new narrow-band two dimensional (2D) materials have been reported. The records of performance of infrared photodetectors based on those 2D materials have been broken, promoting the development of 2D materials family. However, new photoelectric mechanism is needed to be built to solve the scientific problems including large dark current, low photoresponsivity and slow response speed for practical applications of two-dimensional infrared photodetectors. The project aims to study the photoelectric mechanism of two-dimensional materials photodetectors under ferroelectric localized field, heterojunction localized field, subwavelength localized field, and photogating effect localized field. First, we establish some new methods including ferroelectric local field induced PN junction, heterogeneous-junction-induced band engineer, vertical light trapping structure, photogating-effect-induced high gain single photon detection. Secondly, we reveal the influence mechanism of local field effect on dark current and photocurrent. Finally, we solve the key problems of the low signal-to-noise ratio and slow response in two-dimensional infrared photodetector. Our studies offer key technical support for developing next generation to infrared photoelectric detection in China.

近年来，许多新的窄禁带二维材料被相继发现，以此形成的红外光电探测器性能也在不断刷新着记录，一系列具有潜在应用前景的二维材料红外探测器被研制出来。但是，二维材料红外探测器要走向实际应用，急需提出新的光电探测机理来解决暗电流大、光响应低、响应速度慢的深层次科学问题。本项目拟开展铁电局域场、异质结局域场、亚波长局域场、光诱导栅局域场对二维材料的光电调控机理研究。建立局域场调控光电转换新方法，如铁电局域场诱导PN结、异质结局域场能带调控、垂直人工限光结构光场调控、光诱导栅高增益单光子探测，揭示局域场对暗电流和光响应的影响机理，实现对二维材料红外光电探测器的光和电的联合调控，解决二维材料红外光电探测器信噪比低和响应速度慢的核心瓶颈问题，为我国下一代红外光电探测技术的发展提供关键基础支撑。

当前红外光电探测器正在朝着更高工作温度、更高灵敏度、小型化、多维度、仿生智能识别发展。二维窄禁带材料红外探测器具有广泛潜在应用前景，但当前阶段仍然存在暗电流大、光响应低、响应速度慢等问题。为了研究其中的深层次科学问题，本项目围绕局域场调控的二维材料红外光电探测机理及应用开展了异质结、铁电极化、等离子体、光诱导栅等新型局域场的物理起源和应用研究。首先，利用铁电PVDF和LNO的不同极化状态建立了超薄铁电材料与二维材料界面构造方法，发展出新型铁电局域场诱导PN结光电探测机理，研制出具有非对称势垒能带结构的二维材料异质结光电探测原型器件，发展了出单光子探测表征方法以及二维光诱导栅量子放大模型。进一步，基于局域场调控新机制研制出新型3D/2D混合范德华异质结双色红外光电探测器原型器件，实现了二维范德华红外光电探测宽光谱黑体响应。在仿生智能识别方面，研制出基于光诱导栅局域场调控下的双极性正负光电导器件及铁电极化局域场调控下的硅基同质器件，实现了感存算一体的类视网膜动目标识别与光电传感、放大运算、信息存储功能的一体化集成的类脑神经形态架构。通过本项目的实施，为下一代红外探测器的跨代发展提供了关键基础支撑。在Science、Nature Nanotechnology、Nature Electronics等期刊上发表论文35篇，申请中国发明专利14项，其中授权2项，共计培养研究生18名，参加国内外学术交流50次。相关成果被Science和Nature Electronics撰文亮点报道，获“中国光学十大进展”和“中国半导体十大进展”荣誉。项目负责人作为第一完成人获上海市自然科学一等奖（通过答辩），入选中国青年科技奖和科睿唯安全球高被引学者等。