@article{aa6c5edc1f874a8bb20da4f2785a7623,
title = "Charge Separation at Mixed-Dimensional Single and Multilayer MoS2/Silicon Nanowire Heterojunctions",
abstract = "Layered two-dimensional (2-D) semiconductors can be combined with other low-dimensional semiconductors to form nonplanar mixed-dimensional van der Waals (vdW) heterojunctions whose charge transport behavior is influenced by the heterojunction geometry, providing a new degree of freedom to engineer device functions. Toward that end, we investigated the photoresponse of Si nanowire/MoS2 heterojunction diodes with scanning photocurrent microscopy and time-resolved photocurrent measurements. Comparison of n-Si/MoS2 isotype heterojunctions with p-Si/MoS2 heterojunction diodes under varying biases shows that the depletion region in the p-n heterojunction promotes exciton dissociation and carrier collection. We measure an instrument-limited response time of 1 μs, which is 10 times faster than the previously reported response times for planar Si/MoS2 devices, highlighting the advantages of the 1-D/2-D heterojunction. Finite element simulations of device models provide a detailed understanding of how the electrostatics affect charge transport in nanowire/vdW heterojunctions and inform the design of future vdW heterojunction photodetectors and transistors.",
keywords = "MoS, mixed-dimensional heterojunction, nanowire, p-n heterojunction, photodetector, van der Waals",
author = "Alex Henning and Sangwan, {Vinod K.} and Hadallia Bergeron and Itamar Balla and Zhiyuan Sun and Hersam, {Mark C.} and Lauhon, {Lincoln J.}",
note = "Funding Information: *E-mail: lauhon@northwestern.edu. ORCID Alex Henning: 0000-0003-0419-4992 Vinod K. Sangwan: 0000-0002-5623-5285 Itamar Balla: 0000-0002-9358-5743 Zhiyuan Sun: 0000-0003-3981-9083 Mark C. Hersam: 0000-0003-4120-1426 Lincoln J. Lauhon: 0000-0001-6046-3304 Author Contributions All authors have approved the final version of the manuscript. Funding This research was supported by the 2-DARE program (NSF EFRI-1433510) and the Materials Research Science and Engineering Center (MRSEC) of Northwestern University (NSF DMR-1720139). CVD growth of MoS2 was supported by the National Institute of Standards and Technology (NIST CHiMaD 70NANB14H012). Notes The authors declare no competing financial interest. Funding Information: This research was supported by the 2-DARE program (NSF EFRI-1433510) and the Materials Research Science and Engineering Center (MRSEC) of Northwestern University (NSF DMR-1720139). CVD growth of MoS2 was supported by the National Institute of Standards and Technology (NIST CHiMaD 70NANB14H012). A.H. acknowledges the support of a Research Fellowship from the Deutsche Forschungsge-meinschaft (grant HE 7999/1-1). H.B. acknowledges the support from the NSERC Postgraduate Scholarship-Doctoral Program and the National Science Foundation Graduate Research Fellowship. This work made use of the Northwestern University NUANCE Center and the Northwestern University Micro/Nano Fabrication Facility (NUFAB), which are partially supported by the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205), the Materials Research Science and Engineering Center (NSF DMR-1720139), the State of Illinois, and Northwestern University. Publisher Copyright: {\textcopyright} 2018 American Chemical Society.",
year = "2018",
month = may,
day = "16",
doi = "10.1021/acsami.8b03133",
language = "English (US)",
volume = "10",
pages = "16760--16767",
journal = "ACS applied materials & interfaces",
issn = "1944-8244",
publisher = "American Chemical Society",
number = "19",
}