Single and triple insulator Metal-Insulator-Metal diodes for infrared rectennas. (November 2021)

• Record Type: Journal Article
• Authors: Tekin, S.B.; Weerakkody, A.D.; Sedghi, N.; Hall, S.; Werner, M.; Wrench, J.S.; Chalker, P.R.; Mitrovic, I.Z.
• Is Part Of: Solid-state electronics. Volume 185(2021)
• Publication Date: 2021-11
• Subjects: MIM -- Rectenna -- Rectification -- Tunneling -- ALD -- Dielectrics; Semiconductors -- Periodicals; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.sse.2021.108096
• Languages: English
• ISSNs: 0038-1101

Abstract

Highlights: Atomic layer deposition was used to deposit 1–5 nm ultra-thin insulators. Au/Al2 O3 /Ti diode exhibited a zero-bias responsivity of −0.6 A/W. Resonant tunneling effect was observed in triple insulator MI 3 M rectifiers. Experimental I-V characteristics of MI 3 M rectifiers are simulated. Asymmetry of 6 and responsivity of 4.3 A/W at sub-V were obtained for MI 3 M diodes. Abstract: Tunnel-barrier rectifiers comprising single and triple insulator configurations have been fabricated by atomic layer deposition (ALD) to investigate the insulator (Al2 O3, Ta2 O5, Nb2 O5 ) layer quality and rectification performance for inclusion in rectenna arrays for infrared energy harvesting. ALD has provided superior control of nanometer film thickness (1–3 nm) as well as insulator film quality as tunneling has been found to be the dominant conduction mechanism for all fabricated devices. The key rectifier properties, such as asymmetry, non-linearity, responsivity and dynamic resistance have been assessed from current-voltage ( I-V ) measurements. The Au/Al2 O3 /Ti diode exhibits zero bias responsivity of −0.6 A/W, showing that it can be used for energy harvesting applications without the aid of external bias. The effect of resonant tunneling on rectification performance of triple insulator non-cascaded (Ta2 O5 /Nb2 O5 /Al2 O3 ) and cascaded (Nb2 O5 /Ta2 O5 /Al2 O3 ) rectifiers has been observed from experimental I-V characteristics and substantiated by theoretical simulations. Superior low-voltage asymmetry (6 at 0.1 V) and responsivity (4.3 A/W at 0.35 V) for triple insulator MI 3 M rectifiers have been observed. The resonant tunneling does not provide enhanced rectification at low bias as previously reported, rather it has much smaller effect. The latter indicates that dissimilar metal electrodes rectifier configurations are more promising for inclusion in optical rectenna.