Transparent substrate equipped with an electrode
The subject of the invention is a transparent substrate, especially made of glass, which is provided with an electrode, especially for a solar cell, comprising a conductive layer based on molybdenum Mo with a thickness of at most 500 nm, especially at most 400 nm or at most 300 nm or at most 200 nm.
1. A substrate, comprising:
(i) a base,
(ii) an electrode consisting of a conductive layer of molybdenum having a thickness of at least 20 nm and at most 500 nm, and
(iii) a barrier layer provided between the base and the electrode to reduce diffusion of alkali metals,
wherein a resistance per square, R□, of the electrode is less than or equal to 2 Ω/□.
2. The substrate of claim 1 , further comprising an absorbent layer which comprises chalcopyrite.
3. The substrate of claim 1 , wherein the base is glass.
4. The substrate of claim 1 , wherein the thickness of the molybdenum layer is at least 50 nm.
5. The substrate of claim 1 , wherein the thickness of the molybdenum layer is at least 100 nm.
6. The substrate of claim 1 , wherein the thickness of the molybdenum layer is at least 80 nm.
7. The substrate of claim 1 , wherein the barrier layer is a dielectric material selected from the group consisting of silicon nitride, silicon oxynitride, aluminum nitride, aluminum oxynitride, silicon oxide, and silicon oxycarbide.
8. The substrate of claim 1 , wherein the barrier layer has a thickness ranging from 20 nm to 300 nm.
9. The substrate of claim 7 , wherein the barrier layer has a thickness ranging from 100 nm to 200 nm.
10. The substrate of claim 1 , wherein the electrode has a resistance per square, R□, of less than or equal to 1 Ω/□.
11. The substrate of claim 10 , wherein the electrode has a resistance per square, R□, of less than or equal to 0.45 Ω/□.
12. The substrate of claim 1 , wherein the barrier layer is a multilayer coating comprising at least two layers of dielectric material that have different refractive indices.
13. The substrate of claim 12 , wherein the barrier layer comprises a first dielectric material having a refractive index ranging from 1.9 to 2.3 and a second dielectric material having a refractive index ranging from 1.4 to 1.7.
14. The substrate of claim 13 , wherein the barrier layer comprises a first dielectric material and the second dielectric material in the sequence Si 3 N 4 /SiO 2 or Si 3 N 4 /SiO 2 /Si 3 N 4 .
15. The substrate of claim 13 , wherein the substrate has a negative a* value and a negative b* value or a positive a* value and a negative b* value.
16. The substrate of claim 12 , wherein the substrate has a negative a* value and a negative b* value or a positive a* value and a negative b* value.
17. The substrate of claim 1 , further comprising a layer of TiN having a thickness ranging from 2 nm to 15 nm disposed between the barrier layer and the electrode and the substrate has a negative a* value and a negative b* value or a positive a* value and a negative b* value.
18. A solar cell comprising the substrate of claim 1 .
19. The substrate of claim 1 , wherein the electrode is reflective.
20. The substrate of claim 1 , wherein the thickness of the molybdenum layer is at least 200 nm.
21. A method comprising:
providing a base,
providing an electrode consisting of a conductive layer of molybdenum having a thickness of at least 20 nm and at most 500 nm,
providing a barrier layer between the base and the electrode to reduce diffusion of alkali metals,
heating the base, electrode, and the barrier layer in a selenium atmosphere, and
wherein the resistance per square of the electrode remains less than or equal to 2 Ω/□after the heating step.