We can see many varieties of thin film in literature. I like to know what is mean of it. Is it like membranes. Will it be useful in sensors. I like to to know more about it. Is it prepared mechanically or through synthesis.
What the meaning of thin is is actually a good question and I start some of my outreach presentation by addressing that. As always in physics the word thin on its own like big, tall, hot, etc has no meaning. One has to say that something is thin, relative to some characteristic length scale which acts as a natural ruler for comparison. Therefore the meaning of thin is different for optical coating, magnetic or superconducting films, because in all cases the characteristic length scale is different. For an optical coating, dielectric materials on the order of the wavelength of optical light (a few hundred nanometer) can be considered thin. For magnetic films the exchange length is the characteristic length scale which is on the order of a few 0.1 nanometer. For superconducting films it would be the correlation length on which fermions pair into bosons, etc. Similarly a membrane in biology can be called thin because it is like a semipermeable wall separating inside a cell from outside the cell. It is certainly thin compared to the cell dimension but of course not at all thin when compared with nanometric films in many physics applications.
What the meaning of thin is is actually a good question and I start some of my outreach presentation by addressing that. As always in physics the word thin on its own like big, tall, hot, etc has no meaning. One has to say that something is thin, relative to some characteristic length scale which acts as a natural ruler for comparison. Therefore the meaning of thin is different for optical coating, magnetic or superconducting films, because in all cases the characteristic length scale is different. For an optical coating, dielectric materials on the order of the wavelength of optical light (a few hundred nanometer) can be considered thin. For magnetic films the exchange length is the characteristic length scale which is on the order of a few 0.1 nanometer. For superconducting films it would be the correlation length on which fermions pair into bosons, etc. Similarly a membrane in biology can be called thin because it is like a semipermeable wall separating inside a cell from outside the cell. It is certainly thin compared to the cell dimension but of course not at all thin when compared with nanometric films in many physics applications.
We use thin layer - in our situation it means layers of about 250 nm which are made by atomic layer deposition. We use them for sensing physical quantities but it is really very tricky.
I prepare magnetic thin films by sputter deposition. There are a lot of techniques that you can use for thin film deposition. This wikipedia article is a good starting point.
http://en.wikipedia.org/wiki/Thin_film
To add to what has been said.
One can use thin films to make sensors, devices (e.g.LEDs, Solar cells etc), filters etc. Generally they can be prepared by physical methods, chemical methods etc., both by top-down,bottom-up approaches.
One dimension is very small as compared to other two dimensions. Applications in solar cells as photoabsorptive layer, in LED emitting layer, magnetic tapes, filters, membranes many more.
In thin film technology "thin" is a relative term therefore, it can be of orders of micrometer thick and still be thin and it can even be of orders of nanometer to render it self thin. Noticeable application of thin films include thin film stretchable and flexible electronics and energy harvesting devices.
Definition of Thin Film: The ab-initio creation, transportation and condensation of atoms, ions, molecules, clusters etc. in the same form as a layer of material on a substrate & the thickness of the formed layer ranging from fractions of a nanometer to several micrometers.
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