Method of fabricating heterojunction battery
The present invention discloses a method of fabricating a heterojunction battery, comprising the steps of: depositing a first amorphous silicon intrinsic layer on the front of an n-type silicon wafer, wherein the n-type silicon wafer may be a monocrystal or polycrystal silicon wafer; depositing an amorphous silicon p layer on the first amorphous silicon intrinsic layer; depositing a first boron doped zinc oxide thin film on the amorphous silicon p layer; forming a back electrode and an Al-back surface field on the back of the n-type silicon wafer; and forming a positive electrode on the front of the silicon wafer. In addition, the present invention further discloses a method of fabricating a double-sided heterojunction battery. In the present invention, the boron doped zinc oxide is used as an anti-reflection film in place of an ITO thin film; due to the special nature, especially the light trapping effect of the boron doped zinc oxide, the boron doped zinc oxide can achieve good anti-reflection. Therefore, the step of texturization is removed and the fabrication process simplified. As polycrystal silicon texturization is more challenging, the present invention is of more significance to heterojunction batteries using a polycrystal silicon wafer.
1. A method of fabricating a heterojunction battery, comprising the steps of:
a) depositing a first amorphous silicon intrinsic layer on the front of an n-type silicon wafer;
b) depositing an amorphous silicon p layer on the first amorphous silicon intrinsic layer;
c) depositing a first boron doped zinc oxide thin film on the amorphous silicon p layer, wherein the range of the thickness of the first boron doped zinc oxide is between 500 nm and 1000 nm;
d) forming a back electrode and an Al-back surface field on the back of the n-type silicon wafer;
e) forming a positive electrode on the front of the n-type silicon wafer.
2. The method according to claim 1 , wherein the range of the thickness of the first amorphous silicon intrinsic layer is between 5 nm and 30 nm.
3. The method according to claim 1 , wherein the range of the thickness of the amorphous silicon p layer is between 5 nm and 30 nm.
4. A method of fabricating a double-sided heterojunction battery, comprising the steps of:
a) depositing a first amorphous silicon intrinsic layer on the front of an n-type silicon wafer;
b) depositing an amorphous silicon p layer on the first amorphous silicon intrinsic layer;
c) depositing a second amorphous silicon intrinsic layer on the back of the n-type silicon wafer;
d) depositing an amorphous silicon n layer on the second amorphous silicon intrinsic layer;
e) depositing a first boron doped zinc oxide thin film on the amorphous silicon p layer, and depositing a second boron doped zinc oxide thin film on the amorphous silicon n layer;
f) forming a back electrode on the back of the n-type silicon wafer;
g) forming a positive electrode on the front of the n-type silicon wafer.
5. The method according to claim 4 , wherein the range of the thickness of the first amorphous silicon intrinsic layer is between 5 nm and 30 nm.
6. The method according to claim 4 , wherein the range of the thickness of the amorphous silicon p layer is between 5 nm and 30 nm.
7. The method according to claim 4 , wherein the range of the thickness of the second amorphous silicon intrinsic layer is between 5 nm and 30 nm.
8. The method according to claim 4 , wherein the range of the thickness of the amorphous silicon n layer is between 5 nm and 30 nm.
9. The method according to claim 4 , wherein the range of the thickness of the boron doped zinc oxide is between 500 nm and 1000 nm.
10. The method according to claim 5 , wherein the range of the thickness of the boron doped zinc oxide is between 500 nm and 1000 nm.
11. The method according to claim 6 , wherein the range of the thickness of the boron doped zinc oxide is between 500 nm and 1000 nm.
12. The method according to claim 7 , wherein the range of the thickness of the boron doped zinc oxide is between 500 nm and 1000 nm.
13. The method according to claim 8 , wherein the range of the thickness of the boron doped zinc oxide is between 500 nm and 1000 nm.