Scientific Achievement
Helium ion beam manipulation is used to tune the transport behavior in a single layer material, leading to atomically thin circuits.
Significance and Impact
Atomically thin circuits will enable next-generation electronics and optoelectronics.
Research Details
– Selective sputtering in a helium ion microscope locally changes the conduction mechanism in exposed single layers of tungsten diselenide (WSe2) and tungsten disulfide (WS2).
– Scanning transmission electron microscopy combined with electron energy loss spectroscopy and advanced image analysis shows preferential sputtering of selenium.
– First-principle calculations confirm a semiconductor-to-metallic transition induced by pore and edge effects.
– Complete inverters and transistors with an on/off ratio of 106 are achieved in atomically thin circuits.
Image Caption:
(a) Edge contact field effect transistor (FET) in which source and drain contacts consist of modified regions of the single-layer material.
(b) Intensity map of the Raman 2LA(M) peak overlaid on an optical micrograph of a WS2 layer locally exposed to different ion doses.
M.G. Stanford, P. R. Pudasaini, E. T. Gallmeier, N. Cross, L. Liang, A Oyedele, G. Duscher, M. Mahjouri-Samani, K. Wang, K. Xiao, D. B. Geohegan, A. Belianinov, B. G. Sumpter, and P. D. Rack, "High conduction hopping behavior induced in transmission metal dichalcogenides by percolating defect networks: toward atomically thin circuits," Adv. Funct. Mater. (2017). DOI: 10.1002/adfm.201702829
