Univ. Grenoble Alpes , 38000 Grenoble , France.
CEA, LETI, MINATEC Campus , 38000 Grenoble , France.
ACS Appl Mater Interfaces. 2018 Jun 6;10(22):18857-18862. doi: 10.1021/acsami.8b01194. Epub 2018 May 24.
Hybrid systems based on the combination of crystalline bulk semiconductors with 2D crystals are identified as promising heterogeneous structures for new optoelectronic applications. The direct integration of III-V semiconductors on 2D materials is very attractive to make practical devices but the preservation of the intrinsic properties of the underlying 2D materials remains a challenge. In this work, we study the direct epitaxy of self-organized GaN crystals on graphene. We demonstrate that severe metal-organic chemical vapor deposition growth conditions of GaN (chemically aggressive precursors and high temperatures) are not detrimental to the structural quality and the charge carrier mobility of the graphene base plane. Graphene can therefore be used both as an efficient sensitive material and as a substrate for GaN epitaxy to make a self-assembled UV photodetector. A responsivity as high as 2 A W is measured in the UV-A range without any further postprocessing compared to simple deposition of contact electrodes. Our study opens the way to build new self-assembled 2D/III-V hybrid optoelectronic devices by direct epitaxy.
基于将晶体体半导体与二维晶体相结合的混合系统被认为是用于新型光电应用的有前途的异质结构。将 III-V 半导体直接集成到二维材料上对于制造实际器件非常有吸引力，但要保持底层二维材料的固有特性仍然是一个挑战。在这项工作中，我们研究了 GaN 晶体在石墨烯上的直接外延生长。我们证明了 GaN 的直接外延生长条件（化学腐蚀性前体和高温）不会损害石墨烯基底的结构质量和载流子迁移率。因此，石墨烯既可以用作高效灵敏材料，也可以用作 GaN 外延的衬底，以制造自组装的紫外光探测器。与简单沉积接触电极相比，在无需进一步后处理的情况下，在紫外-A 范围内测量到高达 2 A W 的响应度。我们的研究为通过直接外延生长构建新型自组装 2D/III-V 混合光电设备开辟了道路。
