基于二维黑磷/金属纳米复合材料的中红外光探测器研究

Precisely photodetection on infrared light is very important for both civil and military use, because abundant information can be extract from it. As the development of the photodetector on infrared light, the shortcut of the traditional bulk and thin film materials hinder its developing in a device with small size, high performance and low power consumption. It is difficult to meet the increasing demand for infrared photodetector. Two-dimensional black phosphorus has emerged as a promising candidate for infrared photodetectors due to its moderate band gap energy, high carrier mobility, and compatibility with a diverse range of substrates. However, few-layered black phosphorus absorbs a very small portion of the incident light energy because of its ultra-thin thickness, which has incurred many unfavorable limitations in the use of advanced photodetectors, such as low internal gain in the mid infrared region. Here, we propose to graft metallic nanoantennas - gold nanorods on the few-layered black phosphorus in order to enhance the light harvesting performance of the photodetectors. In particular, the enhanced light trapping efficiency and electromagnetic field intensity by the localized surface plasmon resonance of the gold nanorods is expected to increase the internal gain and sensitivity of the proposed photodetector. By optimizing the geometry of Au nanorods, the fabrication recipe of black phosphorus and their composite parameters, we expect that the infrared photoresponsivity of the hetero-structure photodetector be enhanced by 50% compared to pristine counterparts. Our approach opens up a new strategy to engineer surface-plasmon-enhanced optoelectronic devices by active control of the light absorption and conversion efficiency in hybrid semiconductor-metal hetero structures for developing highly sensitive infrared photodetectors.

红外光所含信息丰富，在民用和军用层面实现对其的精确探测十分重要。然而，在红外光探测器向小型化、高性能、低功耗方向发展时却受到传统体材料或薄膜材料尺寸大、能耗高、难调控等缺点的限制，难以满足人们对中红外探测器越来越髙的需求。二维黑磷材料具有媲美硅的高迁移率和极好的光电性质，为开发基于其宽波段、高速度、高响应室温微纳中红外光探测器提供了新思路。本项目拟构建二维黑磷/金属纳米结构异质结构，以研究复合结构中光学吸收增强的机理和能量传递过程为切入点，优化二维材料与金属纳米结构之间光电转换效率，提高器件光探测灵敏度，以满足红外波段光通讯对先进探测器件的要求。通过调节剂纳米粒子的结构参数和优化少层黑磷材料的制备工艺以及在金属纳米粒子在少层黑磷材料表面的覆盖面积，我们预期复合结构的中红外光响应率可以提高50%。可为下一代新型二维半导体和金属纳米复合型中红外光电探测技术的开发提供可靠的理论支持和技术手段。

红外光所含信息丰富，在民用和军用层面实现对其的精确探测十分重要。然而，在红外光探测器向小型化、高性能、低功耗方向发展时却受到传统体材料或薄膜材料尺寸大、能耗高、难调控等缺点的限制，难以满足人们对中红外探测器越来越髙的需求。经过本项目的实施，我们制备二维黑磷/金属纳米复合膜层，并且研究了二维黑磷/金属纳米复合结构之间的相互作用和能量传递过程，最终制备了基于二维黑磷/金属纳米材料的中红外光电探测器。我们开发的黑磷/Graphene/InSe范德华异质结光电探测器，在中红外波段2000nm的辐照实验，结果表明异质结构的响应度和外量子效率比之前黑磷探测器的性能更好。异质结构探测度的实验结果表明，从400nm到2000nm范围探测度都大于10 14 Jones，优于其他二维范德华异质结探测器。除了具有高的探测度，黑磷/Graphene/InSe异质结还具有毫秒量级的响应速度，在2000nm激光测试下，异质结探测器的响应时间达到了1.2s。实验结果表明，石墨烯层可以抑制载流子界面复合，提升载流子寿命，进而提高异质结探测器光响应性能。