Light absorber preform solution and method for making the same

1. A light absorber preform solution, comprising:

a solvent;

a plurality of carbon nanotubes entangled with each other to form a network structure, and

a plurality of carbon particles in the network structure, wherein the plurality of carbon nanotubes and the plurality of carbon particles are in the solvent, and a mass ratio of the plurality of carbon nanotubes and the plurality of carbon particles is in a range from about 4:5 to about 4:70.

2. The light absorber preform solution of claim 1 , wherein the solvent is an organic solvent.

3. The light absorber preform solution of claim 2 , wherein the solvent is ethanol.

4. The light absorber preform solution of claim 1 , wherein the plurality of carbon particles are carbon blacks, and the solvent is ethanol.

5. The light absorber preform solution of claim 1 , wherein the light absorber preform solution consists of the solvent, the plurality of carbon nanotubes, and the plurality of carbon particles.

6. The light absorber preform solution of claim 1 , wherein the plurality of carbon nanotubes are multi-walled carbon nanotubes with an average diameter of 20 nm.

7. The light absorber preform solution of claim 1 , wherein each carbon particle is embedded into the network structure and surrounded by the plurality of carbon nanotubes.

8. The light absorber preform solution of claim 1 , wherein the solvent is greater than or equal to about 50 mL.

9. The light absorber preform solution of claim 8 , wherein the solvent is about 200 mL, the carbon nanotube is about 0.4 g, the mass of the carbon particles is in a range from about 0.5 g to about 7 g.

10. A method for making a light absorber preform solution, comprising:

providing a plurality of carbon nanotubes;

placing the plurality of carbon nanotubes into a solvent and flocculating, to obtain a carbon nanotube suspension being a floccule structure, wherein the plurality of carbon nanotubes in the carbon nanotube suspension are entangled with each other to form a network structure; and

adding a plurality of carbon particles into the carbon nanotube suspension, wherein a mass ratio of the plurality of carbon nanotubes and the plurality of carbon particles is in a range from about 4:5 to about 4:70.

11. The light absorber preform solution of claim 1 , wherein the light absorber preform solution is configured to be sprayed, so that a light absorber is formed, and an absorption rate of the light absorber in a wavelength range of 400 nm to 20 μm is 99.9%.

12. The light absorber preform solution of claim 1 , further comprising a dispersant, wherein the light absorber preform solution consists of the dispersant, the solvent, the plurality of carbon nanotubes, and the plurality of carbon particles.

13. The light absorber preform solution of claim 12 , wherein the dispersant is polyvinylpyrrolidone.

14. The method of claim 10 , wherein the solvent is greater than or equal to about 50 mL.

15. The method of claim 14 , wherein the solvent is about 200 mL, the carbon nanotube is about 0.4 g, the mass of the carbon particles is in a range from about 0.5 g to about 7 g.

16. The method of claim 10 , wherein a method for making the plurality of carbon nanotubes comprises:

growing a carbon nanotube array on a growth substrate; and

scraping the carbon nanotube array from the growth substrate.

17. The method of claim 16 , wherein a method for making the carbon nanotube array comprises:

(a) providing a substantially flat and smooth growth substrate;

(b) forming a catalyst layer on the growth substrate;

(c) annealing the growth substrate with the catalyst layer in air at a temperature in an approximate range from 700 degrees Celsius to 900 degrees Celsius for about 30 to about 90 minutes;

(d) heating the growth substrate with the catalyst layer to a temperature in an approximate range from 500 degrees Celsius to 740 degrees Celsius in a furnace with a protective gas therein; and

(e) supplying a carbon source gas to the furnace for about 5 to about 30 minutes and growing a super-aligned carbon nanotube array on the growth substrate.

18. The method of claim 17 , wherein the super-aligned carbon nanotube array has a height more than 100 microns.