HYBRID CONTACT FOR AND METHODS OF FORMATION OF PHOTOVOLTAIC DEVICES
Described herein is a contact for a photovoltaic device and method of making the same. The contact has a transparent conductive oxide stack, where a first portion of the transparent conductive oxide stack is formed by atmospheric pressure vapor deposition and a second portion of the transparent conductive oxide stack is formed by physical vapor deposition.
1 . A contact for a photovoltaic device, comprising:
a transparent conductive oxide stack of the photovoltaic device, wherein a first portion of the transparent conductive oxide stack is formed by atmospheric pressure chemical vapor deposition and a second portion of the transparent conductive oxide stack is formed by physical vapor deposition.
2 . The contact of claim 1 , wherein the transparent conductive oxide stack comprises a barrier layer, a transparent conductive oxide layer and a buffer layer.
3 . The contact of claim 2 , wherein the barrier layer is formed by atmospheric pressure chemical vapor deposition and the transparent conductive oxide layer and buffer layer are formed by physical vapor deposition.
4 - 5 . (canceled)
6 . The contact of claim 2 , wherein the transparent conductive oxide layer comprises a material selected from the group consisting of F—SnO 2 , Cd 2 SnO 4 , ITO, CIO and ZAO.
7 . The contact of claim 2 , wherein the buffer layer comprises a material selected from the group consisting of SnO 2 , ZnO, In 2 O 3 and ZnSn x O y .
8 . The contact of claim 2 , wherein the buffer layer has a surface roughness mean value of about 5 nm to about 50 nm.
9 . The contact of claim 2 , wherein the barrier layer comprises a first material with a refractive index of about 1.45 to about 1.50 formed over a second material with a refractive index of about 2.0 to about 2.4.
10 . The contact of claim 9 , wherein first material of the barrier layer is selected from the group consisting of SiO 2 , SiAl x O y and Al 2 O 3 .
11 . The contact of claim 9 , wherein the second material of the barrier layer is selected from the group consisting of SiN X , SnO 2 , TiO 2 , Ta 2 O 5 and Nb 2 O 5 .
12 . The contact of claim 1 , further comprising a bond layer formed over the first portion of the transparent conductive oxide stack, wherein the bond layer is formed by physical vapor deposition.
13 . The contact of claim 12 , wherein the bond layer comprises a material selected from the group consisting of SiO 2 and SiAl x O y .
14 . The contact of claim 9 , further comprising a bond layer formed over the barrier layer, wherein the bond layer is formed by physical vapor deposition.
15 . The contact of claim 14 , wherein the bond layer comprises a material selected from the group consisting of SiO 2 and SiAl x O y .
16 . The contact of claim 2 , wherein the barrier layer has a thickness of about 100 Å to about 1000 Å.
17 . The contact of claim 9 , wherein the first material of the barrier layer has a thickness of about 100 Å to about 1000 Å and the second material of the barrier layer has at thickness of about 100 Å to about 1000 Å.
18 . The contact of claim 2 , wherein the transparent conductive oxide layer has a thickness of about 500 Å to about 5000 Å.
19 . The contact of claim 2 , wherein the buffer layer has a thickness of about 50 Å to about 2000 Å.
20 . The contact of claim 12 , wherein the bond layer has a thickness of about 100 Å to about 1000 Å.
21 . The contact of claim 9 , further comprising an APCVD-deposited material underneath the barrier layer, wherein the APCVD-deposited material is selected from the group consisting of SiO 2 , SiAl x O y and Al 2 O 3 .
22 . A photovoltaic device comprising:
a substrate of the photovoltaic device;
a contact, provided over the substrate, comprising:
a barrier layer formed by atmospheric pressure chemical vapor deposition;
a transparent conductive oxide layer formed over the barrier layer, the transparent conductive oxide layer being formed by physical vapor deposition; and
a buffer layer formed over the transparent conductive oxide layer, the buffer layer being formed by physical vapor deposition.
23 - 24 . (canceled)
25 . The photovoltaic device of claim 22 , wherein the transparent conductive oxide layer comprises a material selected from the group consisting of F—SnO 2 , Cd 2 SnO 4 , ITO, CIO and ZAO.
26 . The photovoltaic device of claim 22 , wherein the buffer layer comprises a material selected from the group consisting of SnO 2 , ZnO, In 2 O 3 and ZnSn x O y .
27 . The photovoltaic device of claim 22 , wherein the barrier layer is formed in contact with the substrate.
28 . The photovoltaic device of claim 22 , wherein the barrier layer has a thickness of about 100 Å to about 1000 Å.
29 . The photovoltaic device of claim 22 , wherein the barrier layer comprises a first material with a refractive index of about 1.45 to about 1.50 formed over a second material with a refractive index of about 2.0 to about 2.4.
30 . The photovoltaic device of claim 29 , wherein the first material of the barrier layer is selected from the group consisting of SiO 2 , SiAl x O y and Al 2 O 3 .
31 . The photovoltaic device of claim 29 , wherein the second material of the barrier layer is selected from the group consisting of SiN x , SnO 2 , TiO 2 , Ta 2 O 5 and Nb 2 O 5 .
32 . The photovoltaic device of claim 29 , wherein the first material of the barrier layer has a thickness of about 100 Å to about 1000 Å and the second material of the barrier layer has at thickness of about 100 Å to about 1000 Å.
33 . The photovoltaic device of claim 22 , wherein the transparent conductive oxide layer has a thickness of about 500 Å to about 5000 Å.
34 . The photovoltaic device of claim 22 , wherein the buffer layer has a thickness of about 50 Å to about 2000 Å.
35 . The photovoltaic device of claim 22 , further comprising a bond layer formed over the barrier layer, wherein the bond layer is formed by physical vapor deposition.
36 . The photovoltaic device of claim 35 , wherein the bond layer comprises a material selected from the group consisting of SiO 2 and SiAl x O y .
37 . The photovoltaic device of claim 35 , wherein the bond layer is about 100 Å to about 1000 Å.
38 . The photovoltaic device of claim 29 , further comprising a bond layer formed over the barrier layer, wherein the bond layer is formed by physical vapor deposition.
39 . The photovoltaic device of claim 38 , wherein the bond layer comprises a material selected from the group consisting of SiO 2 and SiAl x O y .
40 . The photovoltaic device of claim 38 , wherein the bond layer has a thickness of about 100 Å to about 1000 Å.
41 . The photovoltaic device of claim 22 , further comprising:
a window layer formed over the buffer layer;
an absorber layer formed over the window layer;
a back contact formed over the absorber layer; and
a back support formed over the back contact.
42 - 44 . (canceled)
45 . The photovoltaic device of claim 22 , wherein the buffer layer has a surface roughness mean value of about 5 nm to about 50 nm.
46 . The photovoltaic device of claim 29 , further comprising an APCVD-deposited material underneath the barrier layer, wherein the APCVD-deposited material is selected from the group consisting of SiO 2 , SiAl x O y and Al 2 O 3 .
47 . A method of forming a photovoltaic device comprising the steps of:
forming a barrier layer over a glass substrate of the photovoltaic device, wherein the barrier layer is formed by atmospheric pressure chemical vapor deposition;
forming a transparent conductive oxide layer over the barrier layer, wherein the transparent conductive oxide layer is formed by physical vapor deposition; and
forming a buffer layer over the transparent conductive oxide layer, wherein the buffer layer is formed by physical vapor deposition.
48 . The method of claim 47 , further comprising the steps of:
forming a window layer over the buffer layer;
forming an absorber layer over the window layer;
forming a back contact over the absorber layer; and
forming a back support over the back contact.
49 . (canceled)
50 . The method of claim 47 , wherein the barrier layer has a thickness of about 100 Å to about 1000 Å.
51 . (canceled)
52 . The method of claim 47 , wherein the transparent conductive oxide layer has a thickness of about 500 Å to about 5000 Å.
53 . (canceled)
54 . The method of claim 47 , wherein the buffer layer has a thickness of about 50 Å to about 2000 Å.
55 . The method of claim 47 , wherein forming the barrier layer comprises forming a first material with a refractive index of about 1.45 to about 1.50 over a second material with a refractive index of about 2.0 to about 2.4.
56 . The method of claim 55 , wherein the first material is selected from the group consisting of SiO 2 , SiAl x O y and Al 2 O 3 .
57 . The method of claim 55 , wherein the second material is selected from the group consisting of SiN x , SnO 2 , TiO 2 , Ta 2 O 5 and Nb 2 O 5 .
58 . The method of claim 55 , wherein the first material of the barrier layer has a thickness of about 100 Å to about 1000 Å and the second material of the barrier layer has at thickness of about 100 Å to about 1000 Å.
59 . The method of claim 47 , further comprising forming a bond layer over the barrier layer, wherein the bond layer is formed by physical vapor deposition.
60 . The method of claim 59 , wherein the bond layer comprises a material selected from the group consisting of SiO 2 and SiAlO x .
61 . The method of claim 59 , wherein the bond layer has a thickness of about 100 Å to about 1000 Å.
62 - 64 . (canceled)
65 . The method of claim 47 , wherein the buffer layer is formed to have a surface roughness mean value of about 5 nm to about 50 nm.
66 . The method of claim 55 , further comprising forming a bond layer over the barrier layer, wherein the bond layer is formed by physical vapor deposition.
67 . The method of claim 66 , wherein the bond layer comprises a material selected from the group consisting of SiO 2 and SiAl x O y .
68 . The method of claim 66 , wherein the bond layer has a thickness of about 100 to about 1000 Å.
69 . The method of claim 55 , further comprising forming an APCVD-deposited material underneath the barrier layer, wherein the APCVD-deposited material is selected from the group consisting of SiO 2 , SiAl x O y and Al 2 O 3 .
70 . A method of forming a contact for a photovoltaic device comprising the steps of:
forming a transparent conductive oxide stack for a photovoltaic device, wherein a first portion of the transparent conductive oxide stack is formed by atmospheric pressure chemical vapor deposition and a second portion of the transparent conductive oxide stack is formed by physical vapor deposition.
71 . The method of claim 70 , wherein the transparent conductive oxide stack comprises a barrier layer, a transparent conductive oxide layer and a buffer layer.
72 . The method of claim 71 , wherein the barrier layer is formed by atmospheric pressure chemical vapor deposition and the transparent conductive oxide layer and the buffer layer are formed by physical vapor deposition.
73 . (canceled)