There are different methods for preparing a nano film. The procedure depends on the desired properties of the coating. All in all I think the cheapest and the most convenient method to prepare a nanocrystalline surface layer is sol-gel method. It does not need any professional equipment to apply a sol-gel layer on the substrate. Furthermore, it is simple and environmentally friendly process.

It depends so much on what exactly are your goals that giving a qualified answer is impossible unless you give more details.

Langmuir-Blodgett (LB) is one of the techniques for obtaining very thin film. However, there are some limitations. You can see the attached chapter written by me essentially dealing with Langmuir monolayers and LB films.

Maybe we let first Blanka point out about what kind of materials she is thinking. We would not want to suggest MBE for polymer films nor LB techniques for iron films...

Self assembly from polymer suspension/dispersion/solution might be a good option. Though you need to find out the appropriate polymer solution concentration. Spin casting might be another option. Self assembly is better than spin casting for such a nano film. However, it might be different for your polymer where solubility, aggregation behaviour and substrate surface properties are the key factors to be considered.

If I were You, I would buy the Atomic Layer Deposition System. You can obtain ultra thin films made of oxides, salts, polymers, organic semiconductors etc. It costs about 200 k EUR.

This is a method employing surface reactions, thus Your thin film (even 1 atom thin!) is homogeneous on whole surface.

Kai is right. We have to know what would You like to obtain. ALD is not suitable for metals deposition (You obtain nanoparticles instead of compact film).

I think doctor blade method and screen printing thin film method is the easy and cheapest technique for obtaining thin film solar cell.

Sorry I didn’t answer to all of you. I do research about technique you suggested. I have developed theoretical method for nanofilms and calculated permittivity, refractive and extinctions coefficient for Frenkel type dielectric. Now I want to verify that model and do experiment. I have problem with finding suitable sample and synthesized them.

dear Blanka Skipina

You please try to verify your model with sol gel synthesis thin films by dip coating for more details you may contact me on [email protected]

Dear Patrizia, Titanium oxide is one good candidate, but I afraid TiO is semiconductor not Frenkel type dielectric. Thanks for paper!

Tanks Sandeap, I have a big dilemma which material to use, do you have something in your mind?

You please try with simple CdS

According to costs of equipment, to anodize Al, Ti, Sn, Au, W You do not need sophisticated equipment. Electrochemical methods, like anodization, are cost effective and "wallet-friendly" in comparison to i.e. Atomic Layer Deposition (500 k EUR). To d the anodization You have to buy a thermostat (about 3 k EUR), DC power supply (about 100 EUR), double walled cell (about 50 EUR), Pt grid (100 EUR), magnetic stirrer (300 EUR) and high purity foil of the element (about 600 EUR) what gives You in total less then 5000 EUR.

Moreover, You can easily obtain nanofilms, due to the fact that anodization is a typical faradic process. To make the process more controllable (slower) researchers use modifiers like Ethylene Glycol. EG is even is used instead of water for anodization in sulfuric acid.

Frenkel-type: The absorption of photons in that dielectric materials can lead to located excitations – Frenkel’s excitons, which are responsible for organic crystals optical characteristics. Frenkel excitons - small dielectric constant with low excitons concentration. I have model for this material.

We have also dielectric with Wannier-Mott excitons - semiconductors, the dielectric constant is generally large.

...and material have to be in crystalline form.

Thermodynamic and general theory of anodization are in the following paper:

Wang et al. Electrochim Acta 62 (2012) 424-432

http://www.sciencedirect.com/science/article/pii/S0013468611018640

There, anodization of Al, Ti, Si, Ge, Sn, Fe, W, Ni, Hf, Nb, Ta, Zr is discussed in terms of thermodynamics and mechanistic studies.

Moreover, due to the anions incorporation, You can dope the oxide with desired anions. for example I have incorporated [Cu(EDTA )]2- chelate anions into the anodic alumina:

http://www.sciencedirect.com/science/article/pii/S0167577X13006630

I think MBE is the best tool to fabricate film at nanoscale resolution. It might be costly but its effective and precise.

Sputtering is used extensively in the semiconductor industry to deposit thin films of various materials in integrated circuit processing. Thin antireflection coatings on glass for optical applications are also deposited by sputtering.

I construct a home made D.C. Sputtering and Magnetron D.C. Sputtering and some things that I borrow from my university.