Anjan Mukherjee: An Imprinting Technique to Fabricate Embedded Single GaAs Nanowire(NW)/Graphene Hybrid Devices

Anjan Mukherjee(1), Dong-chul kim(1,2), Hoyeol Yun(3), Miri Seo(4), Jung Tae Nam(5), Keun Soo Kim(5), Sang Wook Lee(4), A. Mazid Munshi(2), Dasa L. Dheeraj(2), Bjørn-Ove Fimland(1,2), Helge Weman(1,2) (1) Department of Electronic Systems, Norwegian University of Science and Technology, NO-7491, Trondheim, Norway (2) Crayonano As, Otto Nielsens vei 12, NO-7052, Trondheim, Norway (3) School of Physics, Konkuk University, 143 071, Seoul, Republic of Korea (4) Department of Physics, Ewha Womans University,120 750, Seoul, Republic of Korea (5) Department of physics and Graphene Research Institute, Sejong University, 143 747, Seoul, Republic of Korea  Compared to present thin film/graphene optoelectronic devices[1], semiconductor NW/graphene hybrid devices can show additional interesting properties such as light trapping and polarization dependent absorption etc. GaAs is one of the most important lll-V semiconductor NW structure with a high potential for high efficiency solar cells[2] and photo-detectors[3]. In addition, using graphene as highly conducting and transparent electrode could lead to enhance the absorption efficiency of single GaAs NW optoelectronic devices as well as enable basic NW contact studies through a fermi level tunning of the graphene.  In this report, we present the fabrication process of single GaAs NW/graphene hybrid devices with a planar junction configuration. A position-controlled micro transfer and imprinting technique that enables us to choose a single NW (or graphene) selectively on a target graphene (or a single NW) for high quality junction has been developed. Both GaAs NW/graphene bottom-and top-contact devices will be presented. For the fabrication of the first approch, we utilized the weak nature of adhesion between a polymer resist and a hydrophobic surface. For graphene/single NW top- contact devices, a key issue is how to make single NW embedded in a flat-surfaced structure, which is critical for the successful transfer of graphene on top of the NWs. Using a curable photo- resist layer, single NW could be transferred and imprinted for the embedded NW structure.                        [1] Xiaoqiang Li et al., Nano Energy, 16(2015) 310-319 [2] Sander A. Mann et al., Nature Nanotechnology, 11(2016) 1071-1075 [3] FuX. W. et al., Appl. Phys. Lett, 100(2012) 223114 Anjan Mukherjee is currently a PhD student at the Department of Electronic Systems, Norwegian University of Science and Technology(NTNU). He received his MSc. degree from Indian Institute of Technology Delhi(IITD) in 2015. His research is mainly focused at graphene/nanowire devices for optoelectronic applications.