Optical nano-antennas (ONAs) are designed for enhancing light-harvesting efficiency in wireless transmission of optical energy and/or signals, which are of great interests in photodetection or solar energy conversion, particularly in micro-/nanoscale systems such as micro-/nanorobots, implantable sensors, and nanoelectromechanical systems, where self-power is not readily available due to a too small volume of the system itself. A critical challenge for the integration of ONAs is how to rationally place ONAs at the “sweetest” regions in the photoactive devices for more effective photodetection or photovoltaics, which offset the application of ONAs in optoelectronic devices. Here, we exploit a near-infrared pentamer ONAs arrays taking few-layer molybdenum disulfide (MoS₂) as photodetectors to investigate the effect of common locations of ONAs on photocurrent amplification. We show that additional photocurrent amplification (larger than ~ 60% in our devices) can be achieved by placing ONAs close to the depletion regions, i.e., the interface between functional elements and one of the metal electrodes, demonstrating the strong position sensitivity of ONAs on optoelectronic devices. Additionally, the maximum photoresponsivity of few-layer MoS₂ photodetectors under the wavelength of 830 nm had been achieved up to ~ 250 mA/W based on the optical filed enhancement and absorption modulation of MoS₂ nanosheets with our near-infrared pentamer ONAs, indicating its application for near-infrared photodetection. Finally, the maximum responsivity of MoS₂-based nanodevice with pentamer ONA arrays (~ 0.111 mA/W) under self-powered conditions is enhanced by a factor of ~ 7 as against MoS₂-based nanodevice without pentamer ONA arrays. These findings are expected to be valuable for the development of more efficient light-harvesting schemes for both optoelectronic devices and implantable or in-body micro-/nanosystems.

光学纳米天线（ONA）旨在提高光能和/或信号的无线传输中的光收集效率，这在光检测或太阳能转换中尤其是在微/纳米系统（如微//纳米机器人，可植入传感器和纳米机电系统，由于系统本身的体积太小，自供电不易获得。ONA集成的一个关键挑战是如何合理地将ONA放置在光敏器件的“最甜”区域，以实现更有效的光电检测或光伏发电，这抵消了ONA在光电器件中的应用。在这里，我们利用近红外五聚体ONA阵列，该阵列采用了几层二硫化钼（MoS ₂）作为光电探测器，以研究ONA的常见位置对光电流放大的影响。我们表明，通过将ONA置于耗尽区附近（即功能元件和金属电极之一之间的界面）可以实现额外的光电流放大（在我们的设备中大于60％），这表明ONA在电极上的强位置敏感性光电器件。此外，基于我们的近红外五聚体ONA对MoS ₂纳米片的光学增强和吸收调制，在830 nm波长下，几层MoS ₂光电探测器的最大光响应性达到了〜250 mA / W。它在近红外光检测中的应用。最后，MoS的最大响应度与没有五聚体ONA阵列的基于MoS ₂的纳米器件相比，在自供电条件下具有五聚体ONA阵列的基于₂的纳米器件（〜0.111 mA / W）提高了约7倍。这些发现有望为光电器件和可植入或体内微/纳米系统的更有效的光收集方案的开发提供有价值的信息。