If yes, then what should be the value/range of electric filed for the charge transport ?
Please explain .
Please attach some published paper.
Dear Sumruti,
Your question is a basic question concerning the transport mechanisms of electrical conduction an solids. In order to conduct electricity, the material must have free charge carriers. In case of metals the free charges are electrons. In case of semiconductors irrespective of their type, i,e, metallic or organic the materials contains free electrons and holes with concentrations depending on the temperature of the material, its doping and illumination by photons.
These free charges move randomly in a diffusive manner in case of no applied electric field E. There is no net current resulting from this thermal random motion. If an external electric field is applied the free charges drift under the effect of this field resulting in the so called drift velocity vd. It is so that vd= mu E, where mu is the mobility of the material,
So, a material is characterized by a mobility indicating the ability of its charge carriers to drift under the electric field.
It is so that the mobility in organic materials are much smaller than the in the metallic materials because the effective mass is much greater than for metallic semiconductors
because bonding nature in organic materials. The valence electrons are much localized in the organic materials than in the metallic ones.
For more information about the quantitative values please see the Link:
inside.mines.edu/~Zhiwu/research/papers/G02_charge_transfer.pdf
best wishes
Thanks Abdelhalim Sir .
But the paper you given, the range of electric field applied there is 104-106 V/cm. generally this high range of electric field is possible ? If we are applying this much high electric field,then the materials ?
So kindly explain me about the range of electric field that should be applied.
According to Poole-Frenkel formalisms, for disordered materials increased mobility occur at high electric fields. So suppose we are applying this concept for the organic semiconductors case.
Can this much high range of electric fields(104-106 V/cm) be applied to organic molecules ?
Dear Smruti,
The physical limit of the electric field on a semiconductor is its dielectric strength which depends on the strength of its chemical bonds. It may be as high as 10^7 v/cm. So 10^6 is still much less than the critical electric field.
For more information about the effect of eclectic field on the organic semiconductor material follow the Link:
https://www.researchgate.net/publication/230754224_Electric_field-dependent_charge_transport_in_organic_semiconductors
wish you success
Article Electric field-dependent charge transport in organic semiconductors
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