【摘要】 基于多种二维材料的异质结结构能够有效调控并提高器件性能,在光电探测领域拥有巨大的潜力.然而,大多数已报道的基于一类和二类能带结构的异质结器件存在热载流子浓度高的问题,因此光电流和暗电流比值低、并且受到温度的较大影响,导致光电探测器性能受限.本文报道了二碲化钼/六方氮化硼/二碲化钼/六方氮化硼异质结结构中,在无光照及有光照条件下空穴主导的福勒-诺德海姆量子隧穿输运.该器件在室温环境和低于0.3 n Wμm^-2激光功率密度的条件下,实现了高于10⁸的探测率.该器件较快的开关比和高灵敏的探测性能成功地验证了成像功能.将隧穿机制与二维材料多种独特的性质相结合对于新型光电探测器的研究具有重要意义.更多还原

【Abstract】 Heterostructures based on diverse two-dimensional（2D） materials are effective for tailoring and further promoting device performance and exhibit considerable potential in photodetection. However, the problem of high-density thermionic carriers can be hardly overcome in most reported heterostructure devices based on type I and type II band alignment, which leads to an unacceptably small I_photo/I_dark and strong temperature dependence that limit the performance of photodetectors. Here, using the MoTe₂/h-BN/MoTe₂/h-BN heterostructure, we report the hole-dominated Fowler–Nordheim quantum tunneling transport in both on and off states. The state-of-the-art device operating at room temperature shows high detectivity of >108 Jones at a laser power density of <0.3 nW lm^-2 from the visible to near infrared range.In addition, the fast on–off switching and highly sensitive photodetection properties promise superior imaging capabilities. The tunneling mechanism, in combination with other unique properties of 2D materials, is significant for novel photodetection.更多还原