- #1
chpolyz
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In optoelectronics and other nanotechnology applications (like organic photovoltaics, organic LEDs etc) most layers need to be electrically characterized among other types of measurements. Thus, sheet resistance is measured.
An example are the 4-point-probe resistivity measurements. Yet, what happens is to impose current that travels almost horizontally to the surface of the film and measure a voltage between 2 other points of the same surface.
Consider that a movement of charge carriers is realized vertically to the film surface due to voltage, in order to reach the top or bottom electrodes of the device (an organic photovoltaic in this case, which consists of many consecutive sandwiched layers)..
My question is, why do we need to measure the resistance of charge carriers that travel alongside the horizontal surface of a film? In such a way we find the "horizontal" resistance of the film and not the vertical one...
thank you
An example are the 4-point-probe resistivity measurements. Yet, what happens is to impose current that travels almost horizontally to the surface of the film and measure a voltage between 2 other points of the same surface.
Consider that a movement of charge carriers is realized vertically to the film surface due to voltage, in order to reach the top or bottom electrodes of the device (an organic photovoltaic in this case, which consists of many consecutive sandwiched layers)..
My question is, why do we need to measure the resistance of charge carriers that travel alongside the horizontal surface of a film? In such a way we find the "horizontal" resistance of the film and not the vertical one...
thank you