Texturing surface of light-absorbing substrate
Etched substrates, and particularly, light-absorbing etched substrates, and methods for making such substrates are described.
1. A method of texturing a substrate comprising the steps of:
a) coating a layer of particles on a top surface of the substrate;
b) modifying the particles comprising melting the particles to form melted particles that are randomly sized and distributed; and
c) etching the substrate using the modified particles as an etch mask to form randomly-shaped structures.
2. The method of claim 1 , wherein modifying the particles increases an area of contact between at least some of the particles and some of the substrate.
3. The method of claim 1 , wherein the step of modifying the particles further comprises shrinking the particles through reactive-ion-etching or oxygen plasma etching.
4. The method of claim 1 , wherein the step of modifying the particles comprises both shrinking the particles and melting the particles, and shrinking the particles occurs before melting the particles.
5. The method of claim 1 , further comprising removing the modified particles after etching the substrate.
6. The method of claim 1 , wherein the particles are comprised of polymethyl(methacrylate).
7. The method of claim 1 , wherein the layer of particles are dispersed in a solution before coating on the substrate, and a surfactant is added to the solution in which the particles are dispersed.
8. The method of claim 1 , wherein the step of coating comprises one or more of spin coating, dip coating, bar coating, roll coating, knife coating, and spray coating.
9. The method of claim 1 , wherein the substrate is a semiconductor solar sell.
10. The method of claim 9 , wherein the semiconductor solar cell is comprised of silicon, gallium arsenide, copper indium diselenide, or cadmium telluride.
11. The method of claim 1 , wherein the substrate is comprised of glass.
12. The method of claim 1 , wherein the etching comprises wet etching.
13. The method of claim 1 , wherein the etching comprises dry etching.
14. The method of claim 13 , wherein the dry etching comprises sputter etching, reactive ion etching, or ion beam etching.
15. The method of claim 1 , wherein the steps are carried out sequentially.
16. A method of texturing a substrate comprising the steps of:
a) coating a layer of particles on a top surface of the substrate, and modifying the layer of particles comprising melting the particles to form melted particles that are randomly sized and distributed;
b) coating over the layer of particles with a high index of refraction layer to cover the layer of particles,
wherein the material of the high index of refraction layer includes at least one of Si 3 N 4 , ZnS, ZnSe, TiO 2 , ZrO 2 , Al 2 O 3 , HfO 2 , Ta 2 O 5 , and SiON.
17. The method of claim 16 , wherein the step of modifying the layer of particles comprises melting, reactive-ion etching or oxygen plasma etching the particles.
18. The method of claim 1 , wherein the particles at least partially remain on the top surface of the substrate after etching, and the particles form a particle layer having anti-reflective properties.