Tunable two-dimensional interfacial coupling in molecular heterostructures

Beibei Xu; Himanshu Chakraborty; Vivek K Yadav; Zhuolei Zhang; Michael L Klein; Shenqiang Ren

doi:10.1038/s41467-017-00390-1

Tunable two-dimensional interfacial coupling in molecular heterostructures

Nat Commun. 2017 Aug 22;8(1):312. doi: 10.1038/s41467-017-00390-1.

Authors

Beibei Xu^{1

2}, Himanshu Chakraborty^{3

4}, Vivek K Yadav³, Zhuolei Zhang^{1

2}, Michael L Klein^{2

3}, Shenqiang Ren^{5

6}

Affiliations

¹ Department of Mechanical Engineering, Temple University, Philadelphia, PA, 19122, USA.
² Temple Materials Institute, Temple University, Philadelphia, PA, 19122, USA.
³ Department of Chemistry and Institute for Computational Molecular Science, Temple University, Philadelphia, PA, 19122, USA.
⁴ Center for the Computational Design of Functional Layered Materials, Temple University, Philadelphia,, PA, 19122, USA.
⁵ Department of Mechanical Engineering, Temple University, Philadelphia, PA, 19122, USA. shenqiang.ren@temple.edu.
⁶ Temple Materials Institute, Temple University, Philadelphia, PA, 19122, USA. shenqiang.ren@temple.edu.

Abstract

Two-dimensional van der Waals heterostructures are of considerable interest for the next generation nanoelectronics because of their unique interlayer coupling and optoelectronic properties. Here, we report a modified Langmuir-Blodgett method to organize two-dimensional molecular charge transfer crystals into arbitrarily and vertically stacked heterostructures, consisting of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)/C₆₀ and poly(3-dodecylthiophene-2,5-diyl) (P3DDT)/C₆₀ nanosheets. A strong and anisotropic interfacial coupling between the charge transfer pairs is demonstrated. The van der Waals heterostructures exhibit pressure dependent sensitivity with a high piezoresistance coefficient of -4.4 × 10^-6 Pa^-1, and conductance and capacitance tunable by external stimuli (ferroelectric field and magnetic field). Density functional theory calculations confirm charge transfer between the n-orbitals of the S atoms in BEDT-TTF of the BEDT-TTF/C₆₀ layer and the π* orbitals of C atoms in C₆₀ of the P3DDT/C₆₀ layer contribute to the inter-complex CT. The two-dimensional molecular van der Waals heterostructures with tunable optical-electronic-magnetic coupling properties are promising for flexible electronic applications.Two-dimensional van der Waals heterostructures are of interest due to their unique interlayer coupling and optoelectronic properties. Here authors develop a Langmuir-Blodgett method to organize charge transfer molecular heterostructures with externally tunable conductance and capacitance and broadband photoresponse.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.