This document summarizes a presentation given at the University of Liverpool on transparent conducting oxides (TCOs) from an industrial perspective. It discusses how TCOs like fluorine-doped tin oxide are made at an industrial scale using chemical vapor deposition processes and how they are used in applications like energy-efficient windows and solar panels. It also provides an overview of NSG Group, a major glass manufacturer, their TCO products, and their TCO coating processes.

2. 2 Wednesday 12th November 2014 TCO Workshop, University of Liverpool Transparent Conducting Oxides – from an industrial perspective
•How are TCO’s made on an Industrial Scale?
•How are TCO’s used in Industry?
Liam Palmer, NSG Group

3. 3
Liam Palmer – Liam.Palmer@nsg.com
Advanced Technologist, On-line Coatings
NSG European Technical Centre
Lathom, Lancs. UK. European Technical Centre, Lathom Wednesday 12th November 2014 TCO Workshop, University of Liverpool NSG Group R&D Facility

4. Wednesday 12th November 2014 TCO Workshop, University of Liverpool
4
Global Flat Glass Market
•Global market for flat glass in calendar year 2011 was approximately 59 million tonnes.
•At the level of primary manufacture, this represents a value of around €24 billion.
•Most of the world’s float glass goes into buildings. Automotive applications account for around 10 percent.

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NSG Group
• Principal operations in 30 countries
• Ownership/interests in 48 float lines
• Employs around 28,000 people
• Sales in 130+ countries
• €54million investment in R&D in FY2013
• The NSG Group is one of
four glass groups producing
around 50 percent of the
world’s high quality glass.
World-leading supplier of
ultra-thin glass for smart
phones and tablet devices.
Our Ultra Fine Flat Glass (UFF)
is produced in thicknesses as
low as 0.3-1.1mm. NSG annual report 2013
‘Making a Difference to
our World through
Glass Technology’

6. Global Operations
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7. Expansion of Value-Added Business Wednesday 12th November 2014
TCO Workshop, University of Liverpool
7 High value-added products will drive future growth

8. The Float Glass Process
•Pilkington float process is at the heart of the worldwide industry.
•Operates non-stop for 10-15 years
•6000 km/year
•0.3 mm-25 mm thick, up to 3 m wide
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 8 Melting furnace
Float bath
Cooling lehr Continuos ribbon of glass Cross cutters Large plate lift- off devices Small plate lift- off devices
Raw material feed

9. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 9 Transparent Conducting Oxides
•TCOs are used wherever electrical conductivity and transparency are required
•Different applications use different aspects of the TCO properities
•Thin film solar cells make use of the electrical conductivity to collect electrons generated by the photoactive materials
•Glazing applications make use of the high reflectance at long wavelengths

10. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 10
•Low-Emissivity and Solar Control Coatings
•In a double glazed unit, a low-emissivity coating on the inner pane blocks radiative heat trying to escape into the cavity
Low-Emissivity and Solar Control Coatings

11. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 11
•A wide variety of coating technologies are utilised by the glass industry
–Spray Pyrolysis
–Powder Spray
–Chemical Vapour Deposition
–Sputter Coating
–Thermal Evaporation Coatings
–Sol Gel Coatings
•These are applied
–On Line i.e. as the glass is produced on the float line
–Off Line i.e. coating not necessarily produced at the same location
Manufacturing a Functional Coating

12. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 12 Variations of CVD
•Atmospheric Pressure – APCVD
•Low Pressure - LPCVD
•Metalorganic – MOCVD
•Aerosol Assisted – AACVD
•Combustion/Flame – CCVD
•Hot Wire/Filament – HWCVD/HFCVD
•Plasma Enhanced - PECVD
•Laser Assisted – LACVD
•Microwave Assisted – MWCVD
•Atomic Layer Deposition – ALD Broadly termed thermal CVD methods Broadly termed activated CVD methods

13. 3 Main TCO’s
•FTO – Fluorine doped Tin Oxide
•Manufactured by Atmospheric Pressure Chemical Vapour Deposition (APCVD)
•ITO – Indium doped Tin Oxide
•Manufactured by Sputtering, Physical Vapour Deposition (PVD)
•AZO – Aluminium doped Zinc Oxide
•Manufactured by Low Pressure Chemical Vapour Deposition (LPCVD), Plasma Enhanced Chemical Vapour Deposition (PECVD) or Atomic Layer Deposition (ALD)
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 13

14. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 14 Chemical Vapour Deposition Animation kindly supplied by Dr. Warren Cross, University of Leicester

15. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 15 Chemical Vapour Deposition Main gas flow region Gas Phase Reactions Surface Diffusion Desorption of Film Precursor By Products Diffusion to surface

16. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 16 CVD on Glass
For on-line coating of glass we require:
•High growth rates – required thickness in <2 s
•Stable chemistry – uniform coatings for continuous operation for many days
•Good adhesion to glass
•High efficiency – reduce costs

17. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 17 APCVD Strengths and Weaknesses
Strengths
Weaknesses
Result
On-line coating possible
Reduced flexibility
Reduced labour costs, high volume manufacture
Fresh substrate surfaces
No washing step, enhanced adhesion
High deposition rates
Need to match line speed
Thick films possible with high throughput
Hard films
Improved processability and performance
Structure control possible e.g. crystallinity
Rough surface
Improved functional properties and durability
Volatile precursors required
Limited range of materials

18. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 18 Float Glass Plant

19. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 19 Float Glass Plant

20. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 20 Float Glass Plant

21. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 21 Float Glass Plant

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On-Line Coating Position
Load raw
materials
Float line Process
TCO Coated glass supply chain
On-line APCVD
T  650°C
1500 oC
Melting 600 oC
1050 oC
Floating
Cooling

23. Turbulent Flow CVD Coater Wednesday 12th November 2014 TCO Workshop, University of Liverpool 23 Topcoat Beam RHS Section ViewTunnelSkirtAir curtainSkirtAdjustAir curtaininlet pipeWater coolingInoutSlot1Slot2Glass flowExhaust manifoldassemblyExtraction slotDownstreamwater box

24. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 24
•SnCl4 + H2O + HF  SnO2:F + HCl (~1.5 at% F)
•Much gas phase reaction
•Gases introduced separately in turbulent flow regime
•Very high growth rates >100 nm/s possible
•Low precursor efficiency <10% SiCxOy (70 nm) SnO2:F (350 nm) Glass
•SiH4 + C2H4 + CO2  SiCxOy + H2O + other by-products
•Used as colour suppression and barrier layer
CVD of SnO2:F – Pilkington K Glass™ a Low-E Coating

25. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 25 Low Emissivity Coating – Pilkington K Glass™
•SiCO under layer used as a blocking layer and colour suppressant

26. Wednesday 12th November 2014 TCO Workshop, University of Liverpool 26 Laminar Flow CVD Coater Glass Glass Ribbon Flow Up-Stream Exhaust Down-Stream Exhaust Precursor gases Outside Atmosphere

27. CVD of SnO2:F – Common Precursors
•Tin Oxide Precursors
•Dimethyl Tin Dichloride (DMT)
•Monobutyl Tin Trichloride (MBTC)
•Stannic Chloride (SnCl4)
•Fluorine Dopant Precursors
•Hydrogen Fluoride (HF)
•Trifluoro Acetic Acid (TFA / TFAA)
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 27

28. Challenges Facing On-Line Coatings
•Delivering precursors at a constant temperature and flow.
•Maintaining a constant uniformity across a 3 metre ribbon at a speed of up to 15 m/min for as long as possible.
•Longest coatings run time is currently ~60 hours.
•Quality Control – Continuously Inspecting and Monitoring the product being produced.
•Warehouse and other ‘cold-end’ activities.
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29. 3 Main TCO’s
•FTO – Fluorine doped Tin Oxide
•Manufactured by Atmospheric Pressure Chemical Vapour Deposition (APCVD)
•ITO – Indium doped Tin Oxide
•Manufactured by Sputtering, Physical Vapour Deposition (PVD)
•AZO – Aluminium doped Zinc Oxide
•Manufactured by Sputtering, Low Pressure Chemical Vapour Deposition (LPCVD), Plasma Enhanced Chemical Vapour Deposition (PECVD) or Atomic Layer Deposition (ALD)
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30. The Sputtering Process + - Ar Ar+ e- Pumps Process Gas Wednesday 12th November 2014 TCO Workshop, University of Liverpool 30

31. In-Line Production Coater Wednesday 12th November 2014 TCO Workshop, University of Liverpool 31

32. Typical Plant Layout – for Continuous Coating Coating Zone Transfer Chamber Transfer Chamber Load Lock Washing Machine Inspection Room Exit Lock Glass Transport Direction Vacuum Plant Speed Position Leading Edge Speed Wednesday 12th November 2014 TCO Workshop, University of Liverpool
32

33. Sputtering Plant – OLC1 Wednesday 12th November 2014 TCO Workshop, University of Liverpool 33

34. Sputtering Plant – OLC1 Wednesday 12th November 2014 TCO Workshop, University of Liverpool 34

35. Sputtering Plant – OLC1
•£16 million cost for the coater
•£40 million cost for the entire site installation.
•Able to coat ‘Jumbo’ sized plates (6m x 3.21m).
•Able to coat ~10 million m2 a year.
•Ability to produce single and double silver coatings.
•Single silver coatings for Low-E products.
•Double silver coatings for Solar Control products.
•No TCO’s are made at this coater, due to RTP process.
•Able to make TCO’s but not viable as produce FTO.
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 35

36. Comparison – SnO2:F vs ZnO:Al
•ZnO:Al offers better optical and electronic properties over SnO2:F
•After etching AZO significantly enhances light scattering (for silicon devices)
•SnO2:F is more stable than AZO in chemical durability tests.
•SnO2:F is cheaper and more durable than ZnO:Al
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 36

37. NSG Products Wednesday 12th November 2014 TCO Workshop, University of Liverpool 37

38. Coated Products
•Coated Products Divided into 3 groups;
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Building Products
• Low Emissivity
• Solar Control
• Functional Products
NSG TEC™ Products
• Electronic display apps.
• White goods market (freezer lids, etc.)
• OFC Substrates
Solar Products
•Conductive substrates for solar cell fabrication.

39. Pilkington Energy Advantage™
•Pilkington Energy Advantage™ is a low emissivity coating sold predominantly into colder areas of the United States and is basically Pilkington K Glass™ made using oil cooled beams.
•Different precursor chemistry, same end result. Main difference for the end user is slightly more hazy than Pilkington K Glass™ – though we can’t sell Pilkington Energy Advantage™ as Pilkington K Glass™ .
•Low emissivity feature reduces heat loss from a building by reflecting heat back into the building.
•Emissivity is the measure of how efficient the coating is at reflecting heat.
•Clear glass allows ~89% of heat to escape, Pilkington Energy Advantage™ only ~15%.
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40. Pilkington Energy Advantage™
•Pilkington Energy Advantage™ / NSG TEC™ 15 coating is made up of three layers.
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 40

41. Pilkington Energy Advantage™ Wednesday 12th November 2014 TCO Workshop, University of Liverpool 41 Pilkington Energy Advantage™ coating

42. Pilkington Eclipse Advantage™
•Product is a Solar Control coating designed to reduce solar heat from entering a building.
•Designed for commercial building applications and produced on a range of tints to provide aesthetic performance.
•Tint colour is seen from outside of building and not obscured by coating.
•Solar control performance changes with tint.
•Predominantly used on surface #2 of an IGU though can be used as a single pane.
•Glass side reflection dictates how the product looks from the outside.
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43. Pilkington Eclipse Advantage™
•Pilkington Eclipse Advantage™ is made up of four layers.
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 43

44. Pilkington Eclipse Advantage™
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Pilkington Eclipse Advantage™
Coating on #2 Surface

45. NSG TEC™ Products
•NSG TEC™ products developed as a spin off from Pilkington Energy Advantage™ for electronic applications.
•Currently used as;
•Transparent, electrically conductive articles - i.e. heated freezer cabinets.
•TCO Substrates for additional devices – i.e. LCD displays.
•TCO products are basically a variation of top F:SnO2 layer to give different sheet resistance values or morphology.
•Originally made to order products for specific customers but formed the basis of the Solar Energy portfolio.
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 45

46. NSG TEC™ Glass Applications
•Thin Film Photovoltaics
•Electrochromic Mirrors
•Commercial Refrigeration
•Oven Windows/White Goods
•Heated Glass
•Displays
•Sodium blocking for sputter coating processors
•Thermochromics
•Lighting
•Numerous other specialty applications
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 46

47. NSG TEC™ Glass Properties Wednesday 12th November 2014 TCO Workshop, University of Liverpool 47 NSG TEC™ Product Available Thickness (mm) Sheet Resistance (Ohms/square) Visible Transmittance (%) Haze (%) Hemispherical Emittance NSG TEC™ 7 2.2, 3.0, 3.2 6 - 8 80 – 82 5 0.12 NSG TEC™ 8 2.2, 3.2 6 - 9 80 – 81.5 12 0.12 NSG TEC™ 15 2.2, 3.0, 3.2 12-14 82 – 83 ≤0.35 0.15 4.0, 5.0, 6.0, 8, 10 12-14 83 – 84.5 ≤0.75 0.15 NSG TEC™ 20 4.0 19 - 25 80 – 85 ≤0.8 0.21 NSG TEC™ 35 3.2, 6.0 32 - 48 82 – 84 ≤0.65 0.34 NSG TEC™ 50 6.0 43 - 53 80 – 85 ≤0.55 0.38 NSG TEC™ 70 3.2, 4.0 58 - 72 82 – 84 0.5 0.45 NSG TEC™ 250 3.2, 4.0 260 - 325 84– 85 0.7 0.67 NSG TEC™ 1000 3.2 1000 - 3000 88 0.5 0.78

48. NSG TEC™ Products for Solar Applications
•Solar products are based around the Pilkington Energy Advantage™ system with variation in either layer thickness or chemistry.
•Products tend to be manufactured for a single customer rather than same product for multiple customers.
•Products generally form the base plate for solar cells with customers then adding further coatings on top of our materials.
•Solar customers are very strict in terms of specifications and defects – need to qualify the product with each customer.
•Also need products to be exactly the same across each of the manufacturing sites to improve logistics.
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 48

49. NSG TEC™ Glass Properties
•NSG TEC™ products used in the majority of thin film PV technologies.
•TCO properties, optimised for each PV technology.
•Light transmission.
•Coating conductivity.
•Haze.
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 49 Thin film silicon NSG TEC™A8 High haze, rough coating TCO coating Surface roughness CdTe NSG TEC™C15 Low haze, smooth coating TCO coating Surface roughness

50. NSG TEC™ Glass Appliance Applications Wednesday 12th November 2014 TCO Workshop, University of Liverpool 50 Commercial Refrigeration and Freezer Applications Passive Active Curved

51. NSG TEC™ Glass Appliance Applications Wednesday 12th November 2014 TCO Workshop, University of Liverpool 51 Commercial Food Warmers Oven Door Glass

52. Touch Panel Technology -
Resistive
• Resistive touchscreens use a flexible outer membrane that, upon
user touch, forms an electrical circuit with the glass substrate.
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Glass
TEC 1100 – High Resistance Coating
Resistive Coating
Protective Coating
Flexible Membrane
Insulating
Spacers
NSG TEC™

53. Touch Panel Technology -
Capacitive
• Capacitive coupling between a conducting surface and the users
finger draws current from the surface to determine the touch-point
in capacitive screens.
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Glass
TEC SB - Silica Layer
Conductive Coating – TCO (ITO or other)
sodium
Protective Coating
NSG TEC™

54. Touch Panel Applications Wednesday 12th November 2014 TCO Workshop, University of Liverpool 54 Video Gaming Systems Airport Check-In Terminals GPS Systems

55. NSG TEC™ Glass in Heated Windows
•The use of NSG TEC™ Glass for other heated applications is increasing
•Restaurants and residences in cold climates are increasing the comfort level surrounding picture windows.
•Eliminates the cold-shoulder effect with radiant heat.
•Reduces heat loss through the windows and the need to over-heat the entire room to compensate.
•Maintains window clarity and preserves spectacular views.
•Eliminates condensation.
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 55

56. Heated Window Applications
•Residential Application – Exterior
•Photo and Application – Courtesy of Radiant Glass Industries LLC
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57. Heated Window Applications
•Residential Application – Interior
•Photo and Application – Courtesy of Radiant Glass Industries LLC
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58. Heated Window Applications
•Restaurant Application - Mahogany Grille, Durango Colorado
•Photos and Application – Courtesy of thermique™
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59. Industrial Transportation
•Can incorporate active or passive defrosting capability in many applications;
•Military vehicles
•Tank Turrets
•Humvees
•Marine Glazing
•Military
•Private Yacht
•Locomotive glass
•Siemens & General Electric (GE)
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 59

60. Industrial Transportation Wednesday 12th November 2014 TCO Workshop, University of Liverpool 60

61. NSG TEC™ Glass in Electrochromics
•Increasing activity in large area commercial electrochromic development
•Much more difficult application than EC mirrors
•Smart window systems are in development for increased energy management
•Layered film solutions are also in development
•Large scale producers:
•Sage
•View Inc.
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62. Electrochromic Applications
•Photo and Application – Courtesy of Sage Electrochromics, Inc.
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•Club Porticello - Oconomowac, Wisconsin
•Overlooks scenic lake
•Windows face west into setting sun
•Need to preserve view while keeping diners comfortable

63. Electrochromic Applications
•Photo and Application – Courtesy of Sage Electrochromics, Inc.
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 63

64. Summary
•Shown common manufacturing methods for 3 of the main TCO materials;
•Fluorine doped Tin Oxide (FTO) – manufactured by APCVD.
•Indium doped Tin Oxide (ITO) – manufactured by Sputtering.
•Aluminium doped Zinc Oxide (AZO) – manufactured by Sputtering, LPCVD, PECVD or ALD.
•Shown an incite into industrial applications of Transparent Conductive Oxides;
•Low-E, Solar Control and Technical Applications.
•Shown some of the products offered by NSG that use TCO’s.
Wednesday 12th November 2014 TCO Workshop, University of Liverpool 64 Thank you for you attention