Method of making TCO front electrode for use in photovoltaic device or the like
Certain example embodiments of this invention relate to an electrode (e.g., front electrode) for use in a photovoltaic device or the like. In certain example embodiments, a transparent conductive oxide (TCO) based front electrode for use in a photovoltaic device may be made by sputtering a ceramic target in a gaseous atmosphere tailored to optimize the electro-optical properties of the resulting TCO coating. For example, using a particular type of atmosphere in the sputtering process can permit the resulting TCO coating (e.g., of or including zinc oxide, zinc aluminum oxide, and/or ITO) to more readily withstand subsequent high temperature processing which may be used during manufacture of the photovoltaic device. Moreover, processing energy resulting from the high temperature(s) may also optionally be used to improve crystallinity characteristics of the TCO.
1 . A method of making a photovoltaic device, the method comprising:
providing a glass substrate;
sputtering at least one ceramic target in an atmosphere in order to deposit a substantially transparent conductive electrode comprising zinc oxide on the glass substrate;
wherein the ceramic target comprises zinc oxide;
wherein the atmosphere in which the target is sputtered includes both argon and oxygen gas and has an oxygen gas to total gas ratio of from 0.00001 to 0.0025; and
using the glass substrate with at least the electrode thereon in making a photovoltaic device which includes at least one semiconductor film.
2 . The method of claim 1 , wherein said using the glass substrate with at least the electrode thereon in making the photovoltaic device comprises coupling the glass substrate to another glass substrate with at least the electrode and the semiconductor film therebetween.
3 . The method of claim 1 , wherein the semiconductor film comprises amorphous silicon or CdTe.
4 . The method of claim 1 , wherein the photovoltaic device further comprises a back electrode and/or reflector located between at least another glass substrate and the semiconductor film.
5 . The method of claim 1 , wherein the electrode further comprises aluminum, and wherein the electrode contains more zinc than aluminum and has a sheet resistance (R s ) of less than about 50 ohms/square.
6 . The method of claim 1 , wherein the electrode has a sheet resistance (R s ) of no more than about 15 ohms/square.
7 . The method of claim 1 , wherein the electrode further comprises aluminum and the aluminum content of the electrode and/or target is from about 1-5%.
8 . The method of claim 1 , wherein the electrode directly contacts the glass substrate.
9 . The method of claim 1 , further comprising forming an antireflective coating on the glass substrate so that the antireflective coating is located between the glass substrate and the electrode.
10 . The method of claim 1 , wherein the atmosphere in which the target is sputtered has an oxygen gas to total gas ratio of from 0.0001 to 0.002.
11 . The method of claim 1 , wherein the atmosphere in which the target is sputtered has an oxygen gas to total gas ratio of from 0.0001 to 0.0015.
12 . A method of making an electrode for use in an electronic device, the method comprising:
providing a glass substrate;
sputtering at least one ceramic target in an atmosphere in order to deposit a substantially transparent conductive electrode comprising zinc oxide on the glass substrate;
wherein the ceramic target comprises zinc oxide; and
wherein the atmosphere in which the target is sputtered includes both argon and oxygen gas and has an oxygen gas to total gas ratio of from 0.00001 to 0.0025.
13 . The method of claim 12 , further comprising providing a semiconductor film comprising amorphous silicon or CdTe adjacent the electrode.
14 . The method of claim 12 , wherein the electrode further comprises aluminum, and wherein the electrode contains more zinc than aluminum and has a sheet resistance (R s ) of less than about 50 ohms/square.
15 . The method of claim 12 , wherein the electrode further comprises aluminum and the aluminum content of the electrode and/or target is from about 1-5%.
16 . The method of claim 12 , wherein the atmosphere in which the target is sputtered has an oxygen gas to total gas ratio of from 0.0001 to 0.002.
17 . The method of claim 12 , wherein the atmosphere in which the target is sputtered has an oxygen gas to total gas ratio of from 0.0001 to 0.0015.
18 . A method of making a photovoltaic device, the method comprising:
providing a glass substrate;
sputtering at least one ceramic target in an atmosphere in order to deposit a substantially transparent conductive electrode comprising indium tin oxide on the glass substrate;
wherein the ceramic target comprises indium tin oxide;
wherein the atmosphere in which the target is sputtered includes both argon and oxygen gas and has an oxygen gas to total gas ratio of from 0.003 to 0.017; and
using the glass substrate with at least the electrode thereon in making a photovoltaic device which includes at least one semiconductor film.
19 . The method of claim 18 , wherein said using the glass substrate with at least the electrode thereon in making the photovoltaic device comprises coupling the glass substrate to another glass substrate with at least the electrode and the semiconductor film therebetween.
20 . The method of claim 18 , wherein the semiconductor film comprises amorphous silicon or CdTe.
21 . The method of claim 18 , wherein the electrode has a sheet resistance (R s ) of less than about 50 ohms/square.
22 . The method of claim 18 , wherein the electrode directly contacts the glass substrate.
23 . The method of claim 18 , further comprising forming an antireflective coating on the glass substrate so that the antireflective coating is located between the glass substrate and the electrode.
24 . The method of claim 18 , wherein the atmosphere in which the target is sputtered has an oxygen gas to total gas ratio of from 0.004 to 0.016.
25 . The method of claim 18 , wherein the atmosphere in which the target is sputtered has an oxygen gas to total gas ratio of from 0.005 to 0.015.
26 . A method of making an electrode for use in an electronic device, the method comprising:
providing a glass substrate;
sputtering at least one ceramic target in an atmosphere in order to deposit a substantially transparent conductive electrode comprising indium tin oxide on the glass substrate;
wherein the ceramic target comprises indium tin oxide; and
wherein the atmosphere in which the target is sputtered includes both argon and oxygen gas and has an oxygen gas to total gas ratio of from 0.003 to 0.017.
27 . The method of claim 26 , further comprising providing a semiconductor film comprising silicon or CdTe adjacent the electrode.
28 . The method of claim 26 , wherein the atmosphere in which the target is sputtered has an oxygen gas to total gas ratio of from 0.004 to 0.016.
29 . The method of claim 26 , wherein the atmosphere in which the target is sputtered has an oxygen gas to total gas ratio of from 0.008 to 0.014.
30 . The method of claim 26 , wherein the target comprises more indium than tin.