Solution processed, vertically stacked hetero-structured diodes based on liquid-exfoliated WS2 nanosheets: from electrode-limited to bulk-limited behavior
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2022Access:
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Liu, S. and Ding, E.-X. and Kelly, A.G. and Doolan, L. and Gabbett, C. and Kaur, H. and Munuera, J. and Carey, T. and Garcia, J. and Coleman, J.N., Solution processed, vertically stacked hetero-structured diodes based on liquid-exfoliated WS2 nanosheets: from electrode-limited to bulk-limited behavior, Nanoscale, 14, 42, 2022, 15679-15690Abstract:
Vertically stacked metal–semiconductor-metal heterostructures, based on liquid-processed nanomaterials, hold great potential for various printed electronic applications. Here we describe the fabrication of such devices by spray-coating semiconducting tungsten disulfide (WS2) nanosheets onto indium tin oxide (ITO) bottom electrodes, followed by spraying single-walled carbon nanotubes (SWNTs) as the top electrode. Depending on the formulation of the SWNTs ink, we could fabricate either Ohmic or Schottky contacts at the WS2/SWNTs interface. Using isopropanol-dispersed SWNTs led to Ohmic contacts and bulk-limited devices, characterized by out-of-plane conductivities of ∼10−4 S m−1. However, when aqueous SWNTs inks were used, rectification was observed, due to the formation of a doping-induced Schottky barrier at the WS2/SWNTs interface. For thin WS2 layers, such devices were characterized by a barrier height of ∼0.56 eV. However, increasing the WS2 film thickness led to increased series resistance, leading to a change-over from electrode-limited to bulk-limited behavior at a transition thickness of ∼2.6 μm. This work demonstrates that Ohmic/Schottky behavior is tunable and lays the foundation for fabricating large-area 2D nanosheet-based solution-deposited devices and stacks.
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Science Foundation Ireland (SFI)
SFI/12/RC/2278_P2
Author's Homepage:
http://people.tcd.ie/colemajhttp://people.tcd.ie/careyti
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PUBLISHEDcited By 1
Author: Coleman, Jonathan; Carey, Tian
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Nanoscale14
42
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Nanomaterials, Semiconductors, NanosheetsDOI:
http://dx.doi.org/10.1039/d2nr04196kMetadata
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