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Stretch or contraction induced inversion of rectification in diblock molecular junctions
Guang-Ping Zhang1, Gui-Chao Hu, Yang Song
1College of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
The Journal of Chemical Physics
|September 14, 2013
Summary
Stretching or contracting molecular diodes can invert their electrical rectification direction. This mechanical control offers a new way to tune molecular diode performance by altering underlying electronic mechanisms.
Area of Science:
- * Theoretical condensed matter physics.
- * Molecular electronics and nanotechnology.
Background:
- * Molecular diodes are crucial components in nanoscale electronic devices.
- * Understanding and controlling their electrical rectification properties is essential for device applications.
Purpose of the Study:
- * To investigate the impact of mechanical stretching or contraction on the rectification behavior of diblock co-oligomer molecular diodes.
- * To elucidate the underlying electronic mechanisms responsible for rectification and its manipulation.
Main Methods:
- * Utilized ab initio theory and the nonequilibrium Green's function (NEGF) method for theoretical investigations.
- * Analyzed molecular projected self-consistent Hamiltonian, frontier molecular orbitals, and transmission coefficients under external biases.
Main Results:
- * Observed an inversion of the rectifying direction in molecular junctions upon stretching or contraction.
- * Demonstrated that this inversion is dependent on the number of pyrimidinyl-phenyl units within the molecule.
- * Identified asymmetric molecular level shifts and orbital evolution under bias as key competing rectification mechanisms.
Conclusions:
- * The mechanical manipulation of molecular junctions can effectively control and invert electrical rectification.
- * The observed inversion arises from a switch in the dominant rectification mechanism.
- * Mechanically controllable methods provide a feasible route for tuning molecular diode performance.
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