CVD-Grown Monolayer Graphene-Based Geometric Diode for THz Rectennas

Abstract
For THz rectennas, ultra-fast diodes are required. While the metal–insulator–metal (MIM) diode has been investigated in recent years, it suffers from large resistance and capacitance, as well as a low cut-off frequency. Alternatively, a geometric diode can be used, which is more suitable due to its planar structure. However, there is only one report of a THz geometric diode based on a monolayer graphene. It is based on exfoliated graphene, and thus, it is not suitable for mass production. In this work, we demonstrate chemical vapor deposition (CVD)-grown monolayer graphene based geometric diodes, which are mass-producible. The diode’s performance has been studied experimentally by varying the neck widths from 250–50 nm, the latter being the smallest reported neck width for a graphene geometric diode. It was observed that by decreasing the neck widths, the diode parameters such as asymmetry, nonlinearity, zero-bias resistance, and responsivity increased within the range studied. For the 50 nm neck width diode, the asymmetry ratio was 1.40 for an applied voltage ranging from −2 V to 2 V, and the zero-bias responsivity was 0.0628 A/W. The performance of the diode was also verified through particle-in-cell Monte Carlo simulations, which showed that the simulated current-voltage characteristics were consistent with our experimental results.

Citation
Wang, H., Jayaswal, G., Deokar, G., Stearns, J., Costa, P. M. F. J., Moddel, G., & Shamim, A. (2021). CVD-Grown Monolayer Graphene-Based Geometric Diode for THz Rectennas. Nanomaterials, 11(8), 1986. doi:10.3390/nano11081986

Acknowledgements
This research was funded by KAUST (BAS/1/1622-01-01) and KAUST (BAS/1/1346-01-01).

Publisher
MDPI AG

Journal
Nanomaterials

DOI
10.3390/nano11081986

Additional Links
https://www.mdpi.com/2079-4991/11/8/1986

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