@article{b3c1ac4144834ea59a96b2b899c23b46,
title = "Charge Separation in Epitaxial SnS/MoS2 Vertical Heterojunctions Grown by Lowerature Pulsed MOCVD",
abstract = "The weak van der Waals bonding between monolayers in layered materials enables fabrication of heterostructures without the constraints of conventional heteroepitaxy. Although many novel heterostructures have been created by mechanical exfoliation and stacking, the direct growth of 2D chalcogenide heterostructures creates new opportunities for large-scale integration. This paper describes the epitaxial growth of layered, p-type tin sulfide (SnS) on n-type molybdenum disulfide (MoS2) by pulsed metal-organic chemical vapor deposition at 180 °C. The influence of precursor pulse and purge times on film morphology establishes growth conditions that favor layer-by-layer growth of SnS, which is critical for materials with layer-dependent electronic properties. Kelvin probe force microscopy measurements determine a built-in potential as high as 0.95 eV, and under illumination a surface photovoltage is generated, consistent with the expected Type-II band alignment for a multilayer SnS/MoS2 heterostructure. The bottom-up growth of a nonisostructural heterojunction comprising 2D semiconductors expands the combinations of materials available for scalable production of ultrathin devices with field-tunable responses.",
keywords = "KPFM, MOCVD, MoS, SnS, van der Waals heterojunction",
author = "Olding, {Jack N.} and Alex Henning and Dong, {Jason T.} and Qunfei Zhou and Moody, {Michael J.} and Smeets, {Paul J.M.} and Pierre Darancet and Weiss, {Emily A.} and Lauhon, {Lincoln J.}",
note = "Funding Information: This research was supported by the Materials Research Science and Engineering Center (MRSEC) of Northwestern University (NSF DMR-1720139). J.N.O acknowledges Teodor Stanev for help with TEM sample preparation. A.H. acknowledges the support of a Research Fellowship from the Deutsche Forschungsgemeinschaft (grant HE 7999/1-1). M.J.M. gratefully acknowledges support via a 3M Fellowship, as well as from the Ryan Fellowship and the Northwestern University International Institute for Nanotechnology. The authors thank Sarah Rappaport for experimental contributions that informed this work. This work made use of the Northwestern University NUANCE Center, 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. Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. We gratefully acknowledge the computing resources provided on Bebop, a high-performance computing cluster operated by the Laboratory Computing Resource Center at Argonne National Laboratory. This research was supported in part through the computational resources and staff contributions provided for the Quest high performance computing facility at Northwestern University which is jointly supported by the Office of the Provost, the Office for Research, and Northwestern University Information Technology. Publisher Copyright: Copyright {\textcopyright} 2019 American Chemical Society.",
year = "2019",
month = oct,
day = "30",
doi = "10.1021/acsami.9b14412",
language = "English (US)",
volume = "11",
pages = "40543--40550",
journal = "ACS applied materials & interfaces",
issn = "1944-8244",
publisher = "American Chemical Society",
number = "43",
}