Photodetector with superior functional capabilities based on monolayer WO3 developed by atomic layer deposition

Publication date: June 2017
Source:Sensors and Actuators B: Chemical, Volume 245
Author(s): Zhenyin Hai, Mohammad Karbalaei Akbari, Chenyang Xue, Hongyan Xu, Stephen Depuydt, Serge Zhuiykov
Photodetector based on monolayer of tungsten trioxide (WO3) was fabricated by atomic layer deposition (ALD) and its structure and properties were analyzed by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), ellipsometry, atomic force microscopy (AFM), transmission electron microscopy (TEM) and spectrophotometry techniques. The as-developed photodetector exhibited high sensitivity, wide-range photoresponse, extremely fast response time of ∼2.5–2.7ms and superior long-term stability over more than 250 cycles. ALD-enabled Angstrom-precision development of monolayer WO3 with thickness of ∼0.74±0.07nm was done by utilizing (^tBuN)2W(NMe2)2 as tungsten precursor and H2O as oxygen precursor, respectively, without affecting the underlying silicon substrate. The performance of monolayer WO3-based photodetector was much better than that of photodetectors based on other nanostructured WO3, monolayers and few layers of MoS2, MoSe2, GaSe and two-dimensional (2D) ZnO/ZnS nanocomposites. Its fast response speed also enables great application potential in high-frequency light-wave communications, various opto-chemical sensors, photo-switches and optoelectronic circuits.

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