oled glass and material cost & performance...

DOE SSL R&D Workshop January 2013

OLED Glass and Material Cost & Performance Enablers

David P. Maikowski, Guardian Industries Corp.

DOE SSL R&D Workshop OLED Panel Long Beach, CA January 30, 2013


The Promise of OLED Lighting

Source: Canaccord Genuity OLED 101 Report (November 2011)

Window of Opportunity is approaching quickly!

of 6

x6 in

. Dev

ices


OLED Lighting is a promising and attractive SSL technology but at a critical crossroads in terms of potential commercialization > Costs are far above the DOE’s MYP targets and competitive technologies

(ILED, Fluorescent, etc.) > Performance is below the DOE’s MYP targets and competitive technologies > Lifetime is inconsistent and below the DOE’s MYP and competitive

technologies What can be done from a glass and coatings material standpoint to

try and bridge these gaps? > Use of high-grade industrial soda lime glass instead of TFT “display grade”

glass substrates > Use of internal light extraction (between glass substrate and electrode)

instead of external light extraction (outside surface of glass) to double current efficiency

> Use of glass-based encapsulation materials instead of epoxies to realize long-term hermetic seals and, in turn, longer device lifetimes

OLED Lighting at the Crossroads


Competitive Overview OLED Lighting

ILED Lighting

Source: DOE SSL Manufacturing Workshop June 2012


How can we reach the OLED cost goals in the DOE’s most-recent MYP?

The Cost Challenge

Areas in which Guardian has active R&D Projects to address

Source: DOE SSL Manufacturing Workshop June 2012


The vast majority of industrial glass manufactured globally is aimed at traditional flat glass markets other than electronics (although those are the markets growing quickest) > Economies of Scale for glass are obviously most available at processes that

mirror standard flat glass (99% of the market)

Global Glass Capacity Snapshot

99%

55.8%

24.1% 14.7%

5.4% 1%

Source: Guardian Industries Internal Marketing Information

Flat Glass (+ 4% CAGR) Electronic Grade Soda Lime (+22% CAGR)Al Borosilicate TFT (+9% CAGR) Al-Enriched (+22% CAGR)PDP Soda Lime (-4% CAGR)


Specifying “float” soda lime glass with thicknesses > 1.0 mm is one path to realizing the price targets for OLED lighting set by DOE

Substrate Thickness vs. Cost Targets Pr

ice

in $

/sqm

DOE 2015 Cost Target = $5/sqm

Glass Type/Grade and Thickness



Specifying soda lime “float” glass with quality < current “display-grade” glass is another path to realizing the MYP’s cost targets

Substrate Quality vs. Cost Targets

Al Borosilicate Architecture Grade Automotive Grade Electronics Grade TN Grade STN Grade TFT Grade

Surface Scratch L≤50mm L≤30mm W≤0.12mm, L≤7mm, n≤4 W≤0.10mm, L≤5mm, n≤ 4 W≤0.07mm, L≤5mm, n≤3 None

Thickness 3 mm 2 mm 1.1 - 1.6 mm 0.5 - 0.75 mm 0.5 - 0.75 mm 0.5 mmEst. Cost/sqm $3 $2 $4 $8 $20 $38

Soda Lime

Glass Type

< 10-5 mm(< 10 nm)< 0.1 mm

(< 100 um)Att

rib

ute

Surface Defects

In-Body Defects

d≤0.3mm allowed 0.3mm<d≤0.5mm, n≤10 0.5mm<d≤1.5mm, n≤5 d>1.5mm not allowed

d≤0.3mm allowed 0.3mm<d≤0.5mm, n≤10 0.5mm<d≤1.2mm, n≤5 d>1.2mm not allowed

0.15mm≤d<0.2mm, n≤3

0.05mm≤d<0.2mm, n≤2

0.2mm≤d<0.5mm, n≤4

0.15mm≤d<0.5mm, n≤4

0.2mm≤d<0.3mm, n≤3

0.1mm≤d<0.3mm, n≤3

There is no cost-effective path to meet the MYP cost targets if Borosilicate TFT-grade glass is the substrate for OLED lighting regardless of its superior quality (contributes too much to BOM) > A “middle ground” must be established to identify quality levels (and cost-

effective manufacturing processes) that can produce acceptable quality at a reasonable cost without negative impact to device yields



How can we close the performance gap to meet the MYP Targets? The Performance (Efficiency) Challenge

Source: DOE SSL R&D MYP April 2012


Extraction and Electrical Efficiency have been identified as the key enablers to improve overall OLED device efficiency and efficacy > Internal Light Extraction technology the primary path to “move the needle”

Performance Enablers So

urce

: DO

E SS

L R

&D

MYP

Apr

il 20

12


Only 20 to 30% of light is coupled out if standard ITO anode plate (n = 1.8 -2.0) on glass (n = 1.5) is used. Most of the light is trapped inside the device due to the total internal reflection and index mismatching

Need to improve light extraction to realize efficacy performance set by DOE Internal Out Coupling Scattering Layer Stack (OCLS) between the glass and

ITO has the potential to increase light output efficiency by 2.7X > Strategy involves “gradient” optical and “scattering” layers “walking down” the refractive

index from n = 1.75 (for OLED Emissive Layers) to n= 1.9 (for Electrode) to n = 1.5 (for soda lime glass) to minimize losses and maximum light transmission

> Goal is for 2x improvement in efficiency and ability to scale-up to Gen 2.5 substrate

Light Extraction Challenge

OCLS


Device Lifetime Challenge If OLED devices want to reach acceptable, competitive (vs. ILED),

and reliable lifetimes for lighting applications, then they need to employ an encapsulation solution that delivers a long-term hermetic seal and is compatible with the other materials in the device

Source: DOE SSL R&D MYP April 2012

(L70

) Life

time

Hou

rs @

3,0

00 n

its


Extensive testing of potential sealants to glass show that OLED devices need to employ glass-based encapsulation materials (if glass substrates are being used) for long-term hermetic sealing

Encapsulation for Long-Term Lifetime

Efforts need to be focused on developing materials and processes for a cost-effective (< $20/sqm) glass-based edge for hermetic encapsulation without degrading organic materials > Needs be processed at < 120 °C

% T

ML

= T

otal

Mas

s Lo

ss /

Initi

al M

ass • The test objective is to determine

quantitatively the percentage weight loss of material under a maximum pressure of 5X10-5 torr and a temperature of 125 ± 1ºC.

• The percentage of outgassed products that are condensable at a temperature of 25 ± 1ºC under the same vacuum conditions and the amount of water vapor which can be absorbed by the material after the vacuum and temperature exposure are also to be determined.

• For 20-30 year device reliability, we want materials that are < 0% and provide a “hermetic” seal


Current cost and performance issues must be addressed in short order for OLED Lighting to reach its forecasted potential > Positive progress has been made in terms of performance but has been

disjointed from progress on the manufacturing costs side Diligent focus by the OLED technical and manufacturing

community needs to be put on: 1. Arriving at an acceptable glass substrate performance spec that delivers

acceptable yields at reasonable cost (% of BOM) 2. Developing Internal Light Extraction solutions that boost performance by >

2x without significant increasing cost (cannot be a linear relationship) 3. Proving Encapsulation technologies that provide proven long-term hermetic

sealing to ensure lifetime and reliability that do not, in turn, raise production cost or negatively impact manufacturing yields

Summary

oled glass and material cost & performance...

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