PHOTOVOLTAIC DEVICE BARRIER LAYER

1 . A structure, comprising:

a barrier layer adjacent to a substrate, wherein the barrier layer comprises a silicon aluminum oxide;

a transparent conductive oxide layer adjacent to the barrier layer, wherein the transparent conductive oxide layer comprises cadmium and tin; and

a buffer layer adjacent to the transparent conductive oxide layer, wherein the buffer layer comprises tin oxide.

2 . The structure of claim 1 , wherein the substrate comprises a glass.

3 . The structure of claim 2 , wherein the glass is capable of transmitting more than about 50% of light having a wavelength in the range of 400 nm to 850 nm.

4 . The structure of claim 3 , wherein the glass is capable of transmitting more than about 70% of light having a wavelength in the range of 400 nm to 850 nm.

5 . The structure of claim 3 , wherein the glass is capable of transmitting more than about 85% of light having a wavelength in the range of 400 nm to 850 nm.

6 . The structure of claim 1 , wherein the glass comprises a substantially round edge.

7 . The structure of claim 1 , further comprising a second buffer layer between the transparent conductive oxide layer and the tin oxide buffer layer, wherein the second buffer layer comprises an oxide.

8 . The structure of claim 1 , wherein the barrier layer has a thickness of about 500 A to about 1500 A.

9 . The structure of claim 1 , wherein the barrier layer has a thickness of about 1000 A.

10 . The structure of claim 1 , wherein the transparent conductive oxide layer has a thickness of about 1000 A to about 4000 A.

11 . The structure of claim 10 , wherein the transparent conductive oxide layer has a thickness of about 2000 A to about 3000 A.

12 . The structure of claim 11 , wherein the transparent conductive oxide layer has a thickness of about 2600 A.

13 . The structure of claim 1 , wherein the buffer layer has a thickness of about 200 A to about 1500 A.

14 . The structure of claim 13 , wherein the buffer layer has a thickness of less than about 900 A.

15 . The structure of claim 1 , wherein the transparent conductive oxide layer comprises cadmium stannate.

16 . The structure of claim 1 , wherein the barrier layer, the transparent conductive oxide layer, and the buffer layer are annealed.

17 . The structure of claim 16 , further comprising cadmium sulfide-containing semiconductor window layer adjacent to the buffer layer a cadmium telluride-containing semiconductor absorber layer adjacent to the semiconductor window layer.

18 . A photovoltaic device, comprising:

a barrier layer adjacent to a substrate, wherein the barrier layer comprises silicon aluminum oxide;

a transparent conductive oxide layer adjacent to the barrier layer, wherein the transparent conductive oxide comprises cadmium stannate;

a buffer layer adjacent to the transparent conductive oxide layer, wherein the buffer layer comprises tin oxide;

a semiconductor window layer adjacent to the buffer layer and comprising cadmium sulfide; and

a semiconductor absorber layer adjacent to the semiconductor window layer and comprising cadmium telluride.

19 . The photovoltaic device of claim 18 , wherein the substrate comprises a glass.

20 . The photovoltaic device of claim 19 , wherein the glass comprises a reduced iron content.

21 . The photovoltaic device of claim 19 , wherein the glass has a transmittance of about 400 nm to about 850 nm.

22 . The photovoltaic device of claim 19 , wherein the transparent conductive oxide layer is annealed.

23 . The photovoltaic device of claim 22 , wherein the glass has a transmittance percentage of more than about 75%.

24 . The photovoltaic device of claim 23 , wherein the glass has a transmittance percentage of more than about 85%.

25 . The photovoltaic device of claim 19 , wherein one or more edges of the glass is substantially round.

26 . A method of manufacturing a photovoltaic structure comprising:

forming a barrier layer on a substrate, wherein the barrier layer comprises silicon aluminum oxide;

forming a transparent conductive oxide layer adjacent to the barrier layer, wherein the transparent conductive oxide layer comprises cadmium stannate;

forming buffer layer adjacent to the transparent conductive oxide layer, wherein the buffer layer comprises tin oxide; and

annealing the substrate to form an annealed transparent conductive oxide stack adjacent to the substrate.

27 . The method of claim 26 , further comprising forming a semiconductor window layer adjacent to the annealed transparent conductive oxide stack.

28 . The method of claim 27 , further comprising forming a semiconductor absorber layer adjacent to the semiconductor window layer.

29 . The method of claim 26 , wherein the step of forming the barrier layer comprises sputtering in an environment comprising argon and oxygen.

30 . The method of claim 26 , wherein the step of forming the transparent conductive oxide layer comprises sputtering in an environment comprising argon and oxygen.

31 . The method of claim 26 , wherein the step of forming the buffer layer comprises sputtering in an environment comprising oxygen.

32 . The method of claim 26 , further comprising rounding one or more edges of a glass, wherein the substrate comprises the glass.

33 . The method of claim 26 , wherein the annealing comprises heating the stack above about 400 degrees C.

34 . The method of claim 26 , wherein the annealing comprises heating the stack above about 500 degrees C.

35 . The method of claim 26 , wherein the annealing comprises heating the stack below about 600 degrees C.

36 - 49 . (canceled)