高性能低功耗的纳米异质结构铟镓锌氧光电晶体管探测器研究

Presently, nano materials composited IGZO phototransistors have many advantages, such as low fabrication temperature, stable excellent electrical performances and high photoelectric properties (high responsivity and detectivity), which have great application potential in photo-detecting, flexible, wearable device and imaging sensor fields. However, because of the conventional channel's structure, wide-band semiconductor property of IGZO, nano materials and devices' structures, these phototransistors have high power-consumption and a trade-off between many photo-sensing capability. This project is focused on two key problems closely: firstly, reducing the power consumption of phototransistor; secondly, improving photoelectric properties. The characteristics of this project are: 1) the p-i-n photojunction is constructed inside of IGZO channel to guarantee photoelectric properties, to provide carriers' transport barrier and to decrease the device power-consumption. 2) The coupling effect of photoelectric enhancement modes is built to research influence mode for photo-detecting performances in side of 2-dimensional periodic nanostructure and semiconductor heterostructure. This project will continue to optimize and design photo-detecting circuits with high dynamic properties, and provide theoretical and experimental foundation for high-performance and low-consumption phototransistors' broad application in photodetectors.

目前采用纳米材料复合的铟镓锌氧（IGZO）光电晶体管具有制备温度低，电学性能优异和光电特性高（高响应效率、高探测度）等优势，在光电探测、柔性可穿戴设备和图像传感领域有巨大应用潜力。但受到传统IGZO薄膜晶体管沟道结构、宽禁带半导体特性、纳米材料及器件结构等因素的制约，存在光电晶体管功耗过高、光电转换效率和探测速率等光电特性相互掣肘的问题。围绕如何降低光电晶体管器件功耗，提高光电探测性能这两个关键科学问题，本项目提出1）在IGZO沟道内构筑p-i-n异质结构，保证光电性能的同时，形成载流子反向传输势垒，降低器件功耗；2）研究沟道中半导体异质结构及周期性纳米结构引起的多种光电增强模式的耦合，及其对光探测性能的影响模型。在此基础上，本项目将继续优化电路结构，并设计高动态特性探测器电路，最终为高性能低功耗的光电晶体管在光探测领域的广阔应用提供理论支持和实验指导。

本课题针对未来微型化、柔性或可穿戴设备对高灵敏度、低功耗传感器的需求，解决现有纳米材料复合IGZO光感应晶体管探测器功耗高的问题，突破光传感器性能指标间互相制约的技术瓶颈。结合申请人前期对于纳米材料复合IGZO 晶体管及其在阵列电路中应用的研究基础，本项目提出利用低维纳米材料和结构(量子点本征1层和P型的具备周期性纳米结构的二维纳米片)与N型的IGZO有源层在薄膜晶体管沟道中构筑p-i-n的光电异质结。并通过理论分析和实验验证等手段，一方面研究其利用势垒有效降低器件功耗，另一方面研究异质结中多种光电增强模式的耦合机制(包括F-P谐振，表面等离激元，局域场增强效应等)来提高器件的光电响应性能。以这种光感应晶体管为转换核心，优化设计传感器的高灵敏度信号输出电路，消减光电阻塞效应的影响，并制备成(可见红外)光传感器阵列。该光电晶体管探测器不仅具有低工作电压下的低噪声、峰值光响应率为1.26 × 10^6 V/W、低栅压（<3 V）且可灵活调控、探测率为5.8×10^14 Jones等突出优点，完美实现了项目建立时建立的指标，而且还可用于激光光谱探测，并可应用在痕量气体检测等一线光电检测现场。通过本项目的研究，我们揭示了薄膜晶体管沟道内栅电极内嵌电场对异质结能带的调制机理，找到了器件及材料物性与器件电学与光电性能之间的关系，从而推动兼具高光电性能(高灵敏度、高速率)探测和低压低功耗传感的光晶体管探测器的发展，为进一步提升沟道异质结相互作用提供了有力的理论依据，具有重大科学意义和应用价值。