Revealing Fast Cu-Ion Transport and Enhanced Conductivity at the CuInP2S6–In4/3P2S6 Heterointerface

Checa, Martí; Jin, Xin; Millán-Solsona, Rubén; Neumayer, Sabine M.; Susner, Michael A.; McGuire, Michael A.; O’Hara, Andrew; Gomila, Gabriel; Maksymovych, Peter; Pantelides, Sokrates T.; Collins, Liam

doi:10.1021/acsnano.2c06992

Cited by 16 publications

(16 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The line plots of the phase and amplitude also show that there are nonferroelectric states between the ferroelectric domains, as shown in Figure 1f. This discontinuous distribution of ferroelectric domains has also been observed in previous works, 3,14,26,39 indicating the inhomogeneous nature of the layered CIPS. Considering that the piezoresponse mainly relies on the displacement of Cu ions in layered CIPS, the inhomogeneous response is largely reflecting the different degrees of motion in Cu ions.…”

Section: Resultssupporting

confidence: 86%

“…Considering that the piezoresponse mainly relies on the displacement of Cu ions in layered CIPS, the inhomogeneous response is largely reflecting the different degrees of motion in Cu ions. 26,40,41 It is reasonable to conjecture that some of the Cu ions could move out of the lattice, inducing a nonstoichiometric structure with no piezoresponse. These results provide us with a visualized understanding of the inhomogeneity in layered CIPS induced by Cu ion migration, though it is difficult to resolve the exact locations of Cu ions under an electric field in the lattice microscopically.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Robust Threshold-Switching Behavior Assisted by Cu Migration in a Ferroionic CuInP₂S₆ Heterostructure

Zhong

et al. 2023

ACS Nano

View full text Add to dashboard Cite

The two-dimensional layered material CuInP 2 S 6 (CIPS) has attracted significant research attention due to its nontrivial physical properties, including room-temperature ferroelectricity at the ultrathin limit and substantial ionic conductivity. Despite many efforts to control its ionic conductance and develop electronic devices, such as memristors, improving the stability of these devices remains a challenge. This work presents a highly stable threshold-switching device based on the Cu/CIPS/graphene heterostructure, achieved after a comprehensive investigation of the activation of Cu's ionic conductivity. The device exhibits exceptional threshold-switching performance, including good cycling endurance, a high on/off ratio of up to 10 4 , low operation voltages, and an ultrasmall subthreshold swing of less than 1.8 mV/decade for the resistance-switching process. Through temperature-dependent electrical and Raman spectroscopy measurements, the stable resistive-switching mechanism is interpreted with a drifting and diffusion model of Cu ions under the electric field, rather than the conventional conducting filament mechanism. These results make the layered ferroionic CIPS material a promising candidate for information storage devices, demonstrating a compelling approach to achieving high-performance threshold-switching memristor devices.

show abstract

Section: Resultssupporting

confidence: 86%

Section: Resultsmentioning

confidence: 99%

Robust Threshold-Switching Behavior Assisted by Cu Migration in a Ferroionic CuInP₂S₆ Heterostructure

Zhong

et al. 2023

ACS Nano

View full text Add to dashboard Cite

show abstract

“…It has been shown previously by Susner et al. that by varying the Cu/In ratio in CuInP 2 S 6 , a distinct phase segregation into CuInP 2 S 6 regions and In 4/3 P 2 S 6 regions will result. , It may very well be the case that other alloyed transition MCPs may also present phase segregation. This is an important consideration if these alloyed MCPs are to be used in next-generation nanoelectronics as the exfoliated flakes may in fact have different compositions than those expected from the bulk crystals.…”

Section: Introductionmentioning

confidence: 99%

Cation Segregation in Alloyed Thiophosphates Fe_2–xCo_xP₂S₆

et al. 2023

View full text Add to dashboard Cite

Metal thiophosphates are a versatile class of van der Waals materials that can exhibit drastically different properties depending on the metal cations that are incorporated. Solid solutions between different members of this class are of interest to study due to the evolution of the magnetic, topological, and semiconductor properties in these materials. However, there has not yet been a thorough examination of the homogeneity of the cation species within the alloyed system of interest that may prove vital if these thiophosphates are to be incorporated into devices in conjunction with other van der Waals materials. Herein, we report on the structural and chemical differences between measurements of bulk and exfoliated Fe 2−x Co x P 2 S 6 , which were synthesized with a P 2 S 5 flux method. In the bulk, powder X-ray diffraction and scanning electron microscopy energy-dispersive X-ray spectroscopy indicate a homogeneous stoichiometry. This is corroborated by Mossbauer spectroscopy, which in addition suggests that as the quantity of Co introduced into the Fe 2−x Co x P 2 S 6 structure increases, the probability of having the nearest neighbors of any given Fe 2+ cation to be Co 2+ cations is substantially increased. However, upon exfoliation of Fe 2−x Co x P 2 S 6 , Raman spectroscopy and electron energy loss spectroscopy (EELS) measurements suggest that the composition of individual exfoliated flakes deviates significantly from the expected average stoichiometry, and the distribution of Fe 2+ and Co 2+ is not perfectly homogeneous.

show abstract

“…Recently, the utilization of strain engineering to modulate the domain and phase has become a promising method [25,26] . However, there is a lack of key parameters such as elastic coefficient to give accurate reference for the experimental and theoretical investigation of this system [27,28] .…”

Section: Introductionmentioning

confidence: 99%

Elastic properties and Ion-mediated domain switching of self-assembled heterostructures CuInP2S6-In4/3P2S6

2023

Microstructures

View full text Add to dashboard Cite

Van der Waals (vdW) ferroelectric CuInP 2 S 6 (CIPS) has attracted intense research interest due to its unique ferroelectric properties that make it promising for potential applications in flexible electronic devices. A mechanical mean, or so-called strain gradient engineering, has been proven as an effective method to modulate its ferroelectric properties, but the key parameter elastic constants Cij has not been accurately measured. Here, we utilized nanoindentation and contact resonance atomic force microscopy (CR-AFM) techniques to measure the elastic modulus on the (001) plane of nanoscale phase separated CuInP 2 S 6 -In 4/3 P 2 S 6 (CIPS-IPS). The Young's modulus of the CIPS was slightly less than that of the IPS. Density Functional Theory was introduced to obtain the accurate full elastic constant Cij of CIPS and IPS, and we deduced their respective Young's moduli, all of which are in good agreement with our experimental values. We further discovered the asymmetrical domain switching and proposed an ion-mediated domain switching model. The results provide a reliable experimental reference for strain gradient engineering in the phase field simulation in CIPS-IPS.

show abstract

Revealing Fast Cu-Ion Transport and Enhanced Conductivity at the CuInP₂S₆–In_4/3P₂S₆ Heterointerface

Cited by 16 publications

References 66 publications

Robust Threshold-Switching Behavior Assisted by Cu Migration in a Ferroionic CuInP₂S₆ Heterostructure

Robust Threshold-Switching Behavior Assisted by Cu Migration in a Ferroionic CuInP₂S₆ Heterostructure

Cation Segregation in Alloyed Thiophosphates Fe_2–xCo_xP₂S₆

Elastic properties and Ion-mediated domain switching of self-assembled heterostructures CuInP2S6-In4/3P2S6

Contact Info

Product

Resources

About

Revealing Fast Cu-Ion Transport and Enhanced Conductivity at the CuInP2S6–In4/3P2S6 Heterointerface

Cited by 16 publications

References 66 publications

Robust Threshold-Switching Behavior Assisted by Cu Migration in a Ferroionic CuInP2S6 Heterostructure

Robust Threshold-Switching Behavior Assisted by Cu Migration in a Ferroionic CuInP2S6 Heterostructure

Cation Segregation in Alloyed Thiophosphates Fe2–xCoxP2S6

Elastic properties and Ion-mediated domain switching of self-assembled heterostructures CuInP2S6-In4/3P2S6

Contact Info

Product

Resources

About

Revealing Fast Cu-Ion Transport and Enhanced Conductivity at the CuInP₂S₆–In_4/3P₂S₆ Heterointerface

Robust Threshold-Switching Behavior Assisted by Cu Migration in a Ferroionic CuInP₂S₆ Heterostructure

Robust Threshold-Switching Behavior Assisted by Cu Migration in a Ferroionic CuInP₂S₆ Heterostructure

Cation Segregation in Alloyed Thiophosphates Fe_2–xCo_xP₂S₆