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Tunable Injection Barrier in Organic Resistive Switches Based on Phase‐Separated Ferroelectric–Semiconductor Blends
Author(s) -
Asadi Kamal,
de Boer Tom G.,
Blom Paul W. M.,
de Leeuw Dago M.
Publication year - 2009
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200900383
Subject(s) - materials science , ferroelectricity , diode , semiconductor , optoelectronics , bistability , resistive touchscreen , polarization (electrochemistry) , space charge , organic semiconductor , electrode , ferroelectric polymers , dielectric , electrical engineering , electron , chemistry , physics , quantum mechanics , engineering
Organic non‐volatile resistive bistable diodes based on phase‐separated blends of ferroelectric and semiconducting polymers are fabricated. The polarization field of the ferroelectric modulates the injection barrier at the semiconductor–electrode contact and, hence, the resistance of the comprising diodes. Comparison between the on‐ and off‐current of the switching diodes, with the current measured for semiconductor‐only diodes reveals that the switching occurs between bulk‐limited, i.e., space‐charge‐limited, and injection‐limited current transport. By deliberately varying the HOMO energy of the semiconductor and the work‐function of the metal electrode, it is demonstrated that injection barriers up to 1.6 eV can be surmounted by the ferroelectric polarization yielding on/off current modulations of more than five orders of magnitude. The exponential dependence of the current modulation with a slope of 0.25 eV/decade is rationalized by the magnitude of the injection barrier.