Deshpande Preeti, Suri Priyanka, Jeong Hyeon-Ho, Fischer Peer, Ghosh Arindam, Ghosh Ambarish
Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore, India.
Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany.
J Chem Phys. 2020 Jan 31;152(4):044709. doi: 10.1063/1.5138722.
There have been several reports of plasmonically enhanced graphene photodetectors in the visible and the near infrared regime but rarely in the ultraviolet. In a previous work, we have reported that a graphene-silver hybrid structure shows a high photoresponsivity of 13 A/W at 270 nm. Here, we consider the likely mechanisms that underlie this strong photoresponse. We investigate the role of the plasmonic layer and examine the response using silver and gold nanoparticles of similar dimensions and spatial arrangement. The effect on local doping, strain, and absorption properties of the hybrid is also probed by photocurrent measurements and Raman and UV-visible spectroscopy. We find that the local doping from the silver nanoparticles is stronger than that from gold and correlates with a measured photosensitivity that is larger in devices with a higher contact area between the plasmonic nanomaterials and the graphene layer.
已有多篇关于等离子体增强石墨烯光电探测器在可见光和近红外波段的报道，但在紫外波段的报道很少。在之前的一项工作中，我们报道了一种石墨烯-银混合结构在270nm处显示出13A/W的高光响应率。在此，我们考虑这种强光响应背后可能的机制。我们研究了等离子体层的作用，并使用尺寸和空间排列相似的银和金纳米颗粒来考察响应。还通过光电流测量以及拉曼光谱和紫外-可见光谱探究了对混合材料的局部掺杂、应变和吸收特性的影响。我们发现，银纳米颗粒的局部掺杂比金的更强，并且与在等离子体纳米材料和石墨烯层之间具有更高接触面积的器件中测得的更大光敏性相关。
