Process for producing structured coatings

1. A liquid-phase process for producing a structured silicon- and/or germanium-containing coating, comprising:

a) applying at least one coating composition to a substrate, to obtain a coated substrate,

b) partially activating the resulting coating on the coated substrate, and

c) oxidizing a non-activated coating on the substrate,

wherein the coating composition has at least two precursors, of which at least one is a hydridosilane oligomer and at least one is a hydridosilane of the generic formula Si n H 2n+2 with n=3 to 10,

wherein the hydridosilane oligomer is obtainable by thermal reaction of a composition comprising at least one non-cyclic hydridosilane having not more than 20 silicon atoms in the absence of a catalyst at temperatures of less than 235° C.;

wherein the partially activating of the resulting coating in b) refers to a transformation of the deposited precursors of the resulting coating into an amorphous or a crystalline semiconductor coating.

2. The process according to claim 1 , wherein the coating composition comprises at least one solvent and at least one silicon- and/or germanium-containing precursor which is solid or liquid under SATP conditions at 25° C. and 1.013 bar.

3. The process according to claim 1 , wherein one precursor has the generic formula M n X c with M=Si and/or Ge, X=H, F, Cl, Br, I, C 1 -C 10 alkyl, C 1 -C 10 alkenyl, C 5 -C 20 aryl, n≧4 and 2n≦c≦2n+2.

4. The process according to claim 2 , wherein the at least one silicon- and/or germanium-containing precursor is a silicon- and/or germanium-containing nanoparticle.

5. The process according to claim 1 , wherein the hydridosilane of the formula Si n H 2n+2 is branched.

6. The process according to claim 5 , wherein the hydridosilane is isotetrasilane, 2-silyltetrasilane, neopentasilane or a mixture of nonasilane isomers.

7. The process according to claim 1 , wherein the hydridosilane oligomer has a weight-average molecular weight of 200 to 10,000 g/mol.

8. The process according to claim 1 , wherein the hydridosilane oligomer has been obtained by oligomerization of non-cyclic hydridosilanes.

9. The process according to claim 1 , wherein the coating composition is applied in structured form to the substrate.

10. The process according to claim 9 , wherein at least two different coating compositions are applied in structured form, simultaneously or successively and also with or without overlap, to different regions of a substrate.

11. The process according to claim 1 , wherein the oxidizing takes place in an oxygen-containing atmosphere at a temperature≦300° C.

12. The process according to claim 1 , wherein the oxidizing is carried out with an oxidizing agent selected from the group consisting of ozone, carbon dioxide, hydrogen peroxide (H 2 O 2 ), steam (H 2 O), a mono- or polyhydric alcohol, a ketone, a carboxylic acid, a carbonic ester and mixtures comprising trichloroacetic acid and oxygen, and also HCl and oxygen.