Coated article with transparent conductive oxide film doped to adjust Fermi level, and method of making same

• US 7,989,072 B2
• Filed: 10/23/2009
• Issued: 08/02/2011
• Est. Priority Date: 07/05/2005
• Status: Expired due to Fees

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Lu, Yiwei, Krasnov, Alexey
• Primary Examiner(s): Picardat; Kevin M
• Assistant Examiner(s): Au; Bac H
• Application Number:
  US12/588,677
• Publication Number:
  US 20100040892A1
• Time in Patent Office: 648 Days
• Field of Search: 428/426, 428/432, 428/469, 428/472, 428/472.1, 428/472.2, 428/688, 428/689, 428/697, 428/701, 428/702, 359580-582, 359585-586
• US Class Current: 428/432
• CPC Class Codes: C03C 17/245 by deposition from the vapour phase
• CPC Class Codes: C03C 2217/216 ZnO
• CPC Class Codes: C03C 2217/24 Doped oxides
• CPC Class Codes: C03C 2218/154 by sputtering
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3284 Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof
• CPC Class Codes: C04B 2235/3291 Silver oxides
• CPC Class Codes: C04B 2235/402 Aluminium
• CPC Class Codes: C04B 2235/408 Noble metals
• CPC Class Codes: C04B 2235/9653 Translucent or transparent ceramics other than alumina
• CPC Class Codes: C04B 35/453 based on zinc, tin, or bismuth oxides or solid solutions thereof with other oxides, e.g. zincates, stannates or bismuthates
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth

Abstract

A transparent conductive oxide (TCO) based film is formed on a substrate. The film may be formed by sputter-depositing, so as to include both a primary dopant (e.g., Al) and a co-dopant (e.g., Ag). The benefit of using the co-dopant in depositing the TCO inclusive film may be two-fold: (a) it may prevent or reduce self-compensation of the primary dopant by a more proper positioning of the Fermi level, and/or (b) it may promote declustering of the primary dopant, thereby freeing up space in the metal sublattice and permitting more primary dopant to create electrically active centers so as to improve conductivity of the film. Accordingly, the use of the co-dopant permits the primary dopant to be more effective in enhancing conductivity of the TCO inclusive film, without significantly sacrificing visible transmission characteristics. An example TCO in certain embodiments is ZnAlO_x:Ag.

Claims

1. A coated article comprising:

a transparent conductive film provided on a glass substrate;

wherein the transparent conductive film comprises zinc aluminum oxide that is doped with silver in order to enhance electrical properties of the film.

2. The coated article of claim 1, wherein the film includes more zinc than aluminum, and more aluminum than silver.

3. The coated article of claim 1, wherein at least one dielectric layer is provided between the glass substrate and the transparent conductive film.

4. The coated article of claim 1, wherein the coated article has a visible transmission of at least about 50%.

5. The coated article of claim 1, wherein the conductive film comprises at least about 25% zinc, from about 0.5 to 7% aluminum, and from about 0.001 to 3% silver.

6. A coated article comprising:

a transparent conductive film provided on a substrate;

wherein the transparent conductive film comprises MAl oxide that is doped with silver in order to enhance electrical properties of the film.

7. The coated article of claim 6, wherein M is zinc, and wherein there is more Al than Ag present in the film.