Article with transparent conductive oxide coating
A solar cell includes a first substrate having a first surface and a second surface. An underlayer is located over the second surface. A first conductive layer is located over the underlayer. An overlayer is located over the first conductive layer. A semiconductor layer is located over the conductive oxide layer. A second conductive layer is located over the semiconductor layer. The first conductive layer includes a conductive oxide and at least one dopant selected from the group consisting of tungsten, molybdenum, niobium, and/or fluorine.
1 . A method of making a coated article for a solar cell comprising:
supplying a glass substrate having a first surface and a second surface;
applying a first coating over the first surface of the glass substrate;
forming a second coating over the second surface of the glass substrate, wherein the second coating is formed by:
applying an underlayer over the second surface of the glass substrate;
forming a first conductive oxide layer over the underlayer by a chemical vapor deposition process by applying a first metal precursor material comprising a metal to form a first film, and applying a second metal precursor material comprising a metal to form a second film, wherein the first film comprises tin oxide and tungsten and wherein the first film is formed using a tin precursor material and a tungsten precursor material selected from tungsten tetrachloride, and a second film formed over the first film, the second film comprising tin oxide and fluorine;
applying an overlayer over the first conductive oxide layer;
applying a semiconductor layer over the overlayer; and
applying a second conductive layer over the semiconductor layer; and
forming a functional layer over the first surface of the substrate, the functional layer comprising a layer having an average surface roughness in the range of 5 nm to 500 nm and a thickness in the range of 10 nm to 500 nm.
2 . The method of claim 1 , wherein the tin precursor material comprises monobutyltin trichloride.
3 . The method of claim 1 , wherein the forming the first conductive oxide layer step further comprises applying a first dopant precursor material comprising a first dopant with the first metal precursor material.
4 . The method of claim 3 , wherein the first dopant comprises tungsten, and wherein the first film comprises less than 2 wt. % tungsten.
5 . The method of claim 1 , wherein the forming the first conductive oxide layer step further comprises applying a second dopant precursor material comprising a second dopant with the second metal precursor material.
6 . The method of claim 5 , wherein the second dopant comprises fluorine.
7 . The method of claim 1 , wherein the second metal precursor material comprises tin tetrachloride.
8 . The method of claim 1 , wherein the applying the first metal precursor material step is performed before the applying the second metal precursor material step.
9 . The method of making the coated article of claim 1 , wherein the second metal precursor material is different from the first metal precursor material and wherein the first region has a lower haze compared to the second region.
10 . The method of claim 1 , wherein the first film comprises less than 1 wt. % tungsten.
11 . The method of claim 1 , wherein the second film has a lower sheet resistance compared to the first film.
12 . The method of claim 1 , wherein the functional layer comprises a metal oxide selected from silica, alumina, zinc oxide, titania, zirconia, tin oxide, or mixtures thereof.
13 . The method of claim 1 , wherein the functional layer has a root mean square roughness in the range of 100 nm to 250 nm.
14 . The method of claim 1 , wherein the functional layer further comprises an antireflective layer comprising a metal oxide, oxide of metal alloy, nitrides, oxynitrides, or mixtures thereof.
15 . The method of claim 14 , wherein the antireflective layer has a thickness in the range of 5 nm to 600 nm.
16 . The method of claim 1 , further including a light scattering region in and/or on the second surface of the substrate.
17 . The method of claim 16 , wherein the light scattering region comprises nanoparticles.
18 . The method of claim 1 , wherein the first metal precursor material comprises an organo-tin material.