Strong Light-Matter Interactions in Heterostructures of Atomically Thin Films
Strong Light-Matter Interactions in Heterostructures of Atomically Thin Films
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DOI：
10.1126/science.1235547
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发表时间：
2013-06-14
期刊：
影响因子：
56.9
通讯作者：
Novoselov, K. S.
中科院分区：
文献类型：
--
作者：
Britnell, L.;Ribeiro, R. M.;Novoselov, K. S.
各种二维(2D)材料的分离，以及将它们组合在垂直堆栈中的可能性，在材料科学中创造了一种新的范式：基于2D晶体的异质结构。这种概念在超薄和柔性器件领域的许多电子应用中已经被证明是卓有成效的。在这里，我们通过使用半导体过渡金属二卤化物(TMDCs)/石墨烯堆栈将这种结构的范围扩展到光活性结构。TMDC电子态密度的Van Hove奇点保证了增强的光-物质相互作用，导致增强的光子吸收和电子-空穴的产生(收集在透明的石墨烯电极中)。这使得极高效的柔性光伏器件的开发具有高于0.1安培/瓦(相当于外部量子效率高于30%)的光响应度。
The isolation of various two-dimensional (2D) materials, and the possibility to combine them in vertical stacks, has created a new paradigm in materials science: heterostructures based on 2D crystals. Such a concept has already proven fruitful for a number of electronic applications in the area of ultrathin and flexible devices. Here, we expand the range of such structures to photoactive ones by using semiconducting transition metal dichalcogenides (TMDCs)/graphene stacks. Van Hove singularities in the electronic density of states of TMDC guarantees enhanced light-matter interactions, leading to enhanced photon absorption and electron-hole creation (which are collected in transparent graphene electrodes). This allows development of extremely efficient flexible photovoltaic devices with photoresponsivity above 0.1 ampere per watt (corresponding to an external quantum efficiency of above 30%).