Transparent Conducting Oxides An Industrial Perspective

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2 Transparent Conducting Oxides An Industrial Perspective How are TCO s made on an Industrial Scale? How are TCO s used in Industry? Jack Brown- Technologist - NSG Group TCO Workshop, University of Liverpool 2

3 NSG Group R&D Facility European Technical Centre, Lathom Jack Brown Technologist, On-line Coatings NSG European Technical Centre Lathom, Lancs. UK. TCO Workshop, University of Liverpool 3

4 Global Flat Glass Market Glass is generally traded in three main markets, buildings, automotive and special applications. Most of the world s float glass goes into buildings (80%). Automotive applications account for around (10%). The rest is used for other applications TCO Workshop, University of Liverpool 4

5 NSG (Nippon Sheet Glass) Who are we? Where do we operate from? Where are we heading? TCO Workshop, University of Liverpool 5

6 NSG Group The NSG Group is one of four glass groups producing around 50 percent of the world s high quality glass Over 50% of glass is produced in China Principal operations in 28 countries Ownership/interests in 46 float lines Employs around 27,000 people Sales in 130+ countries 54million investment in R&D in FY million investment in R&D in FY2016 TCO Workshop, University of Liverpool 6

7 Global Operations TCO Workshop, University of Liverpool 7

8 Expansion of Value-Added Business High value-added products will drive future growth TCO Workshop, University of Liverpool 8

9 The Float Glass Process Pilkington float process is at the heart of the worldwide industry. Melting furnace Float bath Cooling lehr Continuos ribbon of glass Cross cutters Large plate liftoff devices Small plate liftoff devices Raw material feed Operates non-stop for years 6000 km/year 0.3 mm-25 mm thick, up to 3 m wide TCO Workshop, University of Liverpool 9

10 TCO s Transparent Conducting Oxides What are they? TCO Workshop, University of Liverpool 10

11 Transparent Conducting Oxides TCOs are used wherever electrical conductivity and transparency are required Different applications use different aspects of the TCO properties 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 TCO Workshop, University of Liverpool 11

12 Low-Emissivity and Solar Control Coatings Low-Emissivity and Solar Control Coatings In a double glazed unit, a low-emissivity coating on the inner pane reduces radiation into the cavity TCO Workshop, University of Liverpool 12

13 Manufacturing a Functional Coating 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 TCO Workshop, University of Liverpool 13

14 Variations of CVD Atmospheric Pressure APCVD Low Pressure - LPCVD Metal-organic 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 TCO Workshop, University of Liverpool 14

15 3 Main TCOs 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) TCO Workshop, University of Liverpool 15

16 Basics of APCVD Several stage process culminating in a gas phase reaction to produce a thin film on the glass surface. Nov 2018 ONC Introduction 16

17 Basics of APCVD Vaporisation of a volatile precursor Nov 2018 ONC Introduction 17

18 Basics of APCVD Transport of the chemicals with inert and reactive gases to a suitable reaction chamber. Nov 2018 ONC Introduction 18

19 Basics of APCVD chemical reaction and formation of coating in controlled temperature regime. Nov 2018 ONC Introduction 19

20 Basics of APCVD Removal and neutralisation of by-products Nov 2018 ONC Introduction 20

21 CVD on Glass For on-line coating of glass we require: High growth rates required thickness (00s nm) in <2 s Stable chemistry uniform coatings for continuous operation for many days Good adhesion to glass High efficiency reduce costs can be hard as organometallic precursors used tend to be costly TCO Workshop, University of Liverpool 21

22 APCVD Strengths and Weaknesses Strengths Weaknesses Result On-line coating possible Fresh substrate surfaces High deposition rates Hard films Reduced flexibility Need to match line speed Reduced labour costs, high volume manufacture No washing step, enhanced adhesion Thick films possible with high throughput Improved processability and performance Structure control possible e.g. crystallinity Rough surface Volatile precursors required Improved functional properties and durability Limited range of materials TCO Workshop, University of Liverpool 22

23 Float Glass Plant TCO Workshop, University of Liverpool 23

24 Float Glass Plant TCO Workshop, University of Liverpool 24

25 Float Glass Plant TCO Workshop, University of Liverpool 25

26 Float Glass Plant TCO Workshop, University of Liverpool 26

27 On-Line Coating Position Float line Process TCO Coated glass supply chain T 650 C Load raw materials 1500 o C Melting 1050 o C Floating 600 o C Cooling On-line APCVD TCO Workshop, University of Liverpool 27

28 Turbulent Flow CVD Coater Topcoat Beam RHS Section View Water cooling In out Air curtain inlet pipe Skirt Adjust Exhaust manifold assembly Air curtain Skirt Tunnel Downstream water box Slot1 Slot2 Glass flow Extraction slot TCO Workshop, University of Liverpool 28

29 CVD of SnO 2 :F Pilkington K Glass a Low-E Coating SnO 2 :F (350 nm) SiC x O y (70 nm) Glass SiH 4 + C 2 H 4 + CO 2 SiC x O y + H 2 O + other by-products Used as colour suppression and barrier layer SnCl 4 + H 2 O + HF SnO 2 :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% TCO Workshop, University of Liverpool 29

30 Low Emissivity Coating Pilkington K Glass SiCO under layer used as a blocking layer and colour suppressant TCO Workshop, University of Liverpool 30

31 Laminar Flow CVD Coater 2 nd Gen coaters Up-Stream Exhaust Precursor gases in manifold Down-Stream Exhaust Glass Outside Atmosphere Glass Ribbon Flow TCO Workshop, University of Liverpool 31

32 CVD of SnO 2 :F Common Precursors How could we make it more efficient? Tin Oxide Precursors Dimethyl Tin Dichloride (DMT) Monobutyl Tin Trichloride (MBTC) Stannic Chloride (SnCl 4 ) Fluorine Dopant Precursors Hydrogen Fluoride (HF) Trifluoro Acetic Acid (TFA / TFAA) TCO Workshop, University of Liverpool 32

33 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. TCO Workshop, University of Liverpool 33

34 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) TCO Workshop, University of Liverpool 34

35 The Sputtering Process Process Gas - Ar + e- + Pumps TCO Workshop, University of Liverpool 35

36 In-Line Production Coater TCO Workshop, University of Liverpool 36

37 Speed Typical Plant Layout for Continuous Coating Vacuum Plant Washing Machine Load Lock Transfer Chamber Coating Zone Transfer Chamber Exit Lock Inspection Room Glass Transport Direction Leading Edge Speed Position TCO Workshop, University of Liverpool 37

38 Sputtering Plant OLC1 TCO Workshop, University of Liverpool 38

39 Sputtering Plant OLC1 TCO Workshop, University of Liverpool 39

40 Sputtering Plant OLC1 Not Pilkington Technology 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 m 2 a year. Ability to produce single and double silver coatings (not triple, yet ) Single silver coatings for Low-E products. Double silver coatings for Solar Control products. Able to make TCO s but not as viable as FTO already produced at UK5 TCO Workshop, University of Liverpool 40

41 Comparison SnO 2 :F vs ZnO:Al ZnO:Al offers better optical and electronic properties over SnO 2 :F After etching AZO significantly enhances light scattering. This is a benefit for materials that don t absorb well at long wavelengths SnO 2 :F is more stable than AZO in chemical durability tests. SnO 2 :F is cheaper than ZnO:Al TCO Workshop, University of Liverpool 41

42 NSG Products TCO Workshop, University of Liverpool 42

43 Coated Products Coated Products Divided into 3 groups; 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. TCO Workshop, University of Liverpool 43

44 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. Like discussed before, do not use Stannic Chloride, instead use DMT. 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%. TCO Workshop, University of Liverpool 44

45 Pilkington Energy Advantage Pilkington Energy Advantage / NSG TEC 15 coating is made up of three layers. TCO Workshop, University of Liverpool 45

46 Pilkington Energy Advantage Pilkington Energy Advantage coating TCO Workshop, University of Liverpool 46

47 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. TCO Workshop, University of Liverpool 47

48 Pilkington Eclipse Advantage Pilkington Eclipse Advantage is made up of four layers. TCO Workshop, University of Liverpool 48

49 Pilkington Eclipse Advantage Pilkington Eclipse Advantage Coating on #2 Surface TCO Workshop, University of Liverpool 49

50 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:SnO 2 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. TCO Workshop, University of Liverpool 50

51 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 TCO Workshop, University of Liverpool 51

52 NSG TEC Glass Properties NSG TEC Product Available Thickness (mm) Sheet Resistance (Ohms/square) Visible Transmittance (%) Haze Hemispherical Emittance (%) NSG TEC 7 2.2, 3.0, NSG TEC 8 2.2, NSG TEC , 3.0, , 5.0, 6.0, 8, NSG TEC NSG TEC , NSG TEC NSG TEC , NSG TEC , NSG TEC TCO Workshop, University of Liverpool 52

53 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. TCO Workshop, University of Liverpool 53

54 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. Thin film silicon NSG TEC A8 High haze, rough coating Surface roughness CdTe NSG TEC C15 Low haze, smooth coating TCO coating Surface roughness TCO coating TCO Workshop, University of Liverpool 54

55 NSG TEC Glass Appliance Applications Commercial Refrigeration and Freezer Applications Passive Active Curved TCO Workshop, University of Liverpool 55

56 NSG TEC Glass Appliance Applications Commercial Food Warmers Oven Door Glass TCO Workshop, University of Liverpool 56

57 Touch Panel Applications NSG TEC SB (capacitive), NSG TEC 1100 (Resistive) Airport Check-In Terminals GPS Systems Video Gaming Systems TCO Workshop, University of Liverpool 57

58 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. TCO Workshop, University of Liverpool 58

59 Heated Window Applications Residential Application Exterior Photo and Application Courtesy of Radiant Glass Industries LLC TCO Workshop, University of Liverpool 59

60 Heated Window Applications Residential Application Interior Photo and Application Courtesy of Radiant Glass Industries LLC TCO Workshop, University of Liverpool 60

61 Heated Window Applications Restaurant Application - Mahogany Grille, Durango Colorado Photos and Application Courtesy of thermique TCO Workshop, University of Liverpool 61

62 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) TCO Workshop, University of Liverpool 62

63 Industrial Transportation TCO Workshop, University of Liverpool 63

64 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. TCO Workshop, University of Liverpool 64

65 Electrochromic Applications Club Porticello - Oconomowac, Wisconsin Overlooks scenic lake Windows face west into setting sun Need to preserve view while keeping diners comfortable Photo and Application Courtesy of Sage Electrochromics, Inc. TCO Workshop, University of Liverpool 65

66 Electrochromic Applications Photo and Application Courtesy of Sage Electrochromics, Inc. TCO Workshop, University of Liverpool 66

67 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. Thank you for you attention TCO Workshop, University of Liverpool 67

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