Research Article OLED Fabrication by Using a Novel Planar ...

Research ArticleOLED Fabrication by Using a Novel PlanarEvaporation Technique

Fu-Ching Tung12 Yi-Shan Wang2 Shih-Hsiang Lai2 Chien-Chih Chen2 Szu-Hao Chen2

Ching-Chiun Wang2 Jwo-Huei Jou1 and Sun-Zen Chen3

1 Department of Materials Science and Engineering National Tsing Hua University Hsinchu 30013 Taiwan2Mechanical and Systems Research Laboratories Industrial Technology Research Institute Hsinchu 31040 Taiwan3 Center for Nanotechnology Materials Science and Microsystems National Tsing Hua University Hsinchu 30013 Taiwan

Correspondence should be addressed to Fu-Ching Tung fctungitriorgtw and Jwo-Huei Jou jjoumxnthuedutw

Received 13 March 2014 Revised 15 May 2014 Accepted 23 May 2014 Published 22 June 2014

Academic Editor Liang-Sheng Liao

Copyright copy 2014 Fu-Ching Tung et alThis is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Organic light-emitting diode fabrication is suffering from extremely high material wasting during deposition especially using atypical point or even line sourceMoreover the need of depositing a high number of emitters and host(s) with a precise compositioncontrol in a single layer makes traditional vapor codeposition systems nearly impossible unless otherwise with a very low yieldTo improve we have developed a novel thin-film deposition system with a planar source loadable with any premetered solvent-mixed organic compounds plausibly with no component number limitation We hence demonstrate experimentally along with aMonte Carlo simulation in the report the feasibility of using the technique to deposit on a large area-size substrate various organicmaterials with a relatively high material utilization rate coupling with high film uniformity Specifically nonuniformity of less thanplusmn5 and material utilization rate of greater than 70 have been obtained for the studied films

1 Introduction

Organic light-emitting diodes (OLEDs) emit light whenelectricity is applied They are used to create beautifuldigital displays and also possible for use in solid-statelighting applications in the near future [1ndash3] Howeverthey are not the mainstream technologies yet because ofthe high manufacturing cost To resolve some key tech-nologies need to be significantly improved if not totallyreplaced

Amongst organic thin-film deposition process is onekey technology in OLEDs manufacturing Most in use areevaporation systems equipped with a point source Althoughthe point source provides good film nonuniformity incase the source-to-substrate distance is sufficiently long thematerial utilization rate is known to be much less than10 [4 5] The high waste of those expensive organicmaterials is one major cause of the current high cost inOLEDs manufacturing This in turn obstructs the market

acceptance The problem becomes more severe as large area-size panels are demanded To overcome we propose a novelevaporation system equipped with a planar source loadablewith any premetered solvent-mixed organic compounds Itis a promising technology that can markedly improve thematerial utilization rate and easily scale up for deposition oflarge area-size substrate to enable low-costmanufacturing forOLED devices In current study we demonstrate a successfulOLED device manufacturing by using in part the newlydeveloped systemThenew systemhas shown a better organicfilm uniformity and a higher material utilization than theconventional ones

To assist the design of the new system a paral-lel direct simulation Monte Carlo (DSMC) method [6]has been adopted in order to attain high film unifor-mity on a large area-size substrate for various differ-ent organic materials The DSMC [6] method can beapplied in several applications including semiconduc-tor related fabrication processes fluidthermal analysis of

Hindawi Publishing CorporationInternational Journal of PhotoenergyVolume 2014 Article ID 683037 8 pageshttpdxdoiorg1011552014683037

2 International Journal of Photoenergy

Substrate

Vapor flow

Organicmaterials

Evaporationsource plate

Heater

(a) (b)

Figure 1 Illustration of (a) the concept and (b) photograph of the novel evaporation system

Set initial state andread system data

Start

Move all molecules

Enter new molecules

Sort (index) molecules

Collide molecules

Sample flow field

Resetsampling data

Print out the data

Stop

Reach steady flow

Sufficientsampling

No

NoYes

Yes

(a) (b)

Figure 2 (a) Flow chart of the 3D DSMCmethod and (b) the 3D simulation cells

MEMSNEMS devices hypersonic flow analysis estima-tion of spacecraft and scramjet engines flow Impor-tantly it can also be adopted for modeling thin-filmdeposition process such as in the present case the physicalvapor evaporation of OLED to obtain high uniformity onlarge area-size substrates for mixed compounds with anydesignated concentration [7ndash10]

It is learned that via an accurate DSMC modelingthe development cost of the system can be tremendouslyreduced and the operational conditions of which can berapidly optimized It is also observed that the film uni-formity is greatly improved and material utilization rate ismarkedly enhanced as the target-to-source (TS) distance isdecreased

International Journal of Photoenergy 3

EML II (TPBi )

Cathode (LiFAl)

ETL (Bmpypb)

EML I (TcTa)

HTL (TAPC)

HIL (PEDOT PSS)

ITO glass

Figure 3 The structure of OLED device manufactured

2 Experimental

21 Novel Evaporation System Equipped with a Planar SourcePlate The planar source module is illustrated in Figure 1(a)[11] First organic materials are deposited on the planarsource plate by using a coating process The planar sourceplate is then placed in a chamberThe heater under the planarsource plate heats to the desired temperature and the organicmaterials on the planar source plate are deposited upwardonto the glass substrate A shutter plate is set between theplanar source plate and substrate to prevent the impurityfrom evaporating to the substrate at the initial time of theevaporation The chamber is pumped to base pressure byusing a cryopump equipped with a controlled gate valveFigure 1(b) presents a photograph of the novel evaporationsystem equipped with a planar source plate

22 Parallel Direct Simulation Monte Carlo Method Thedirect simulation Monte Carlo (DSMC) method involvesdirectly simulating particle collision kinetics for solving theBoltzmann equation and can automatically capture nonequi-librium phenomena without any convergence problem Thismethod has been widely used for simulating gas flow in rar-efied gas dynamics In addition the parallel DSMC methodcan mitigate the problem of high computing power andincreased computational time by simulating a large numberof particles [12ndash15]

We applied parallel DSMC for modeling the transportphenomena and film deposition in an OLED process-ing chamber containing the planar source plate Althoughnumerous particles are generated in the flowfield to representreal physical gas molecules the DSMC algorithm can bereadily parallelized using physical domain decompositionEach processor executes the DSMC algorithm in sequencefor all of the particles and cells of the computational gridwhich are distributed among the processors in its domainData communication occurs when particles cross the domain(processor) boundaries and are then transferred betweenprocessors

Figure 2(a) presents a simplified flow chart of thethree-dimensional (3D) DSMC method used in this studyFigure 2(b) presents the 3D simulation cells of the planarsource system Table 1 lists the properties of OrganicMaterial

Table 1 The properties of Organic Material A

Item ValueMolecular weight 45943Molecular mass (kg) 763119864 minus 26

Ref temperature (K) 273Surface temperature (∘C) 155Surface temperature (K) 428Flux 119869 (molem2

sdots) 807119864 minus 10

Flux 119899 (m2sdots) 486119864 + 14

Mean thermal speed (ms) 444119864 + 02

Number density 119899 (m3) 109119864 + 12

Degrees of freedom 120585 3Viscosity coefficient 329119864 minus 05

Viscosity index 120596 163Reference diameter 119889 (m) 176119864 minus 09

Mean free path 120582 150119864 + 02

A [11] According to the simulation result we modified theplanar source plate used in this study to achieve optimalperformance

23 Methods and Device Fabrication The thickness of theAlq3 thin films deposited using the planar source platewas measured to assess the nonuniformity of the filmthickness We deposited organic material (5 6 11 12)-tetraphenylnaphthacene (rubrene) onto the glass substrateat varying distances between the target substrate and planarsource plate (TS) to measure the material utilization of theplanar source plate

Figure 3 presents the structure of the fabricated OLEDdevice The substrate size is 5 times 5 cm

First we fabricated a hole-injection layer (HIL) on aprecleaned indium tin oxide (ITO) anode by spin-coating anaqueous solution of poly(34-ethylene-dioxythiophene)-poly(styrenesulfonate) (PEDOTPSS) in nitrogen

The hole-transport layer (HTL) was then deposited usingthe proposed system equipped with the planar source plateWe used di-[4-(NN-ditolyl-amino)-phenyl]cyclohexane(TAPC) as the hole-transport material The TAPC wasdissolved in tetrahydrofuran spray-coated onto the planarsource plate at room temperature in air and driedThe heaterheated to 450∘C and the TAPC was deposited upward ontothe glass substrate exhibiting a TS gap of 5 cm at a pressureof 133 Pa

The other organic and metal layers were prepared usinga conventional system at approximately 133 times 10minus3 Pa A441015840410158401015840-tris(carbazol-9-yl)-triphenylamine (TcTa) was usedas the host with a small amount of blue dopant for the emis-sive layer (EML) I A 135-tris(1-phenyl-1 h-benzimidazol-2-yl) benzene (TPBi) was used as host with a small amount ofred dopant yellow dopant and green dopant for the EMLII Subsequently 13-bis[35-di (pyridin-3-yl) phenyl]benzene(Bmpypb) was prepared to form an electron-transport layer(ETL)


Num

ber d

ensit

y (

m3)

79E + 16

53E + 16

36E + 16

24E + 16

16E + 16

11E + 16

73E + 15

49E + 15

33E + 15

22E + 15

15E + 15

10E + 15

(a)

64E + 16

44E + 16

30E + 16

21E + 16

14E + 16

96E + 15

66E + 15

45E + 15

31E + 15

21E + 15

15E + 15

10E + 15

Num

ber d

ensit

y (

m3)

(b)

Figure 4 Number density distribution diagrams with (a) 30mm and (b) 150mm TS distance (slice from x-y plane)

35E minus 04

24E minus 04

16E minus 04

11E minus 04

75E minus 05

51E minus 05

34E minus 05

23E minus 05

16E minus 05

11E minus 05

74E minus 06

50E minus 06

Pres

sure

(Pa)

(a)

Pres

sure

(Pa)

26E minus 04

18E minus 04

13E minus 04

90E minus 05

63E minus 05

44E minus 05

30E minus 05

15E minus 05

10E minus 05

72E minus 06

50E minus 06

21E minus 05

(b)

Figure 5 Pressure distribution diagrams with (a) 30mm and (b) 150mm TS distance (slice from x-y plane)

Effect of gap distance (source diameter 200 mm)

0

10

20

30

40

50

60

70

80

90

100

10 20 30 60 90 120 150Gap distance (mm)

Uniformity ()Material utilization efficiency ()

Uni

form

ity (

)m

ater

ial u

tiliz

atio

n effi

cien

cy (

)

Figure 6 The relationship of thin-film uniformity and materialutilization rate of Organic Material A at varying TS gap distances

Subsequently an electron-injection layer (EIL) of lithiumfluoride (LiF) and aluminum cathode was deposited usingthermal evaporation at 133 times 10minus3 Pa

Y

Z

X

18E minus 07

18E minus 07

17E minus 07

17E minus 07

16E minus 07

16E minus 07

15E minus 07

15E minus 07

Mas

s flux

(kg

m2

s)

Figure 7 Mass flux of Organic Material A

Luminance chromaticity and electroluminescence spec-tra of the OLEDs were recorded using a PR-650 Spec-traScanColorimeterThe current-voltage characteristicsweremeasured using a Keithley 2400 source meter All of themeasurements were performed at room temperature inair


Table 2 Thickness of the ldquoAlq3rdquo thin films deposited by the planar source

Position 1 2 3 4 5 6 7 8Thickness (nm) 15171 14959 15082 15353 16103 15464 15215 15846

Table 3 Material utilization rate of the planar source

TS (cm) Planar source plate weightdifference (mg)

Substrate weight difference(mg) Material utilization rate ()

14 142 47 33112 136 57 41910 54 42 778

1 2 3 4 5 6 7 8

Figure 8 The thickness measurement positions of the substrate

3 Results and Discussion

31 Parallel Direct Simulation Monte Carlo Method Figure 4presents the number density contour for observing thedistribution from the evaporation source to the substrateTheflux ofmolecules from the evaporation source to the substrateis uniform when the TS distance is equal to 30mm Figure 5illustrates the pressure distribution contour for a TS distanceof (a) 30mm and (b) 150mm (slice from the x-y plane)The pressure distribution at a TS distance of 30mm is moreuniform than that at a TS distance of 150mm [11] becausetilted blade gate openings as indicated by the ldquordquo in Figures4 and 5 were constructed to obstruct the flow to reducethe influence of the asymmetrical pumping system Becausethe TS gap was short and the pressure was considerablylow the influence of the asymmetrical system was reducedAlthough the molecules number density and the pressuredistribution were not symmetrical near the outlet regionboth were symmetrical in the region of the substrate and thetarget High film uniformity was thus obtained

Figure 6 presents the relationship of thin-film uniformityand material utilization rate of Organic Material A at varyingTS gap distances The uniformity of the thin film is morethan 85 when the TS distance ranges from 30mm to

150mm The thin-film thickness uniformity and materialutilization rate are high when the TS distance is decreasedwhich differs from the conventional thermal evaporationsystem equipped with a point source

The film uniformity can be estimated according to themass flux of the particles passing through the substratesurface as illustrated in Figure 7 As indicated the mass fluxis distributed from 15 times 10minus7 to 18 times 10minus7 kgm2s with mostof the mass flux centered from 16 times 10minus7 to 18 times 10minus7 kgm2sEquations (1)ndash(3) are used to calculate the nonuniformityBecause of the high uniformity of particle distribution thecalculated film nonuniformity is only 35 Consider

119879 =1

119873

119873

sum

119894=1

119905119894

(1)

Δ119905 = radic1

119899 minus 1

119873

sum

119894=1

(119905119894minus 119879)

2 (2)

UN = Δ119905119879

times 100 (3)

where 119879 is the mass flux average119873 is the total mass flux 119905119894is

the mass flux Δ119905 is the standard deviation of mass flux andUN is the nonuniformity number

32 Nonuniformity of the Film Thickness The thin filmscomposed of tris(8-hydroxy-quinolinato) aluminum (Alq3)were deposited using the planar source plate at a distanceof 5 cm between the target substrate and planar source plate(TS)

The thickness of the Alq3 thin films was measured usingthe Dektak XT Surface Profiler as indicated in Table 2 [11]The positions measured from the 10 times 10 cm glass substrateare presented in Figure 8 The nonuniformity of the filmthickness can be determined using (4) Consider

Nonuniformity (plusmn) =(119879max minus 119879min)

2119879avgtimes 100 (4)

where 119879max 119879min and 119879avg are the maximal minimal andaverage values of the film thickness respectively Accordingto (4) the nonuniformity of the Alq3 thin-film thickness was


180

160

140

120

100

80

60

40

20

03 35 4 45 5 55 6 65

Voltage (V)

Curr

ent d

ensit

y (A

m2)

(a)

3 35 4 45 5 55 6 765

Volts (V)

Lum

inan

ce (c

dm

2)

5000

4000

3000

2000

1000

0

(b)

Luminance (cdm2)500040003000200010000

35

30

25

20

15

10

Pow

er effi

cien

cy (l

mW

)

(c)

Figure 9 (a)The current density-voltage characteristic (b)The brightness-voltage characteristic (c) The power efficiency versus luminanceof the OLED device

Figure 10 The OLED device illuminated at 35 V

plusmn37The uniformity can be easily attained using the planarsource plate at a short TS distance [11]

A layer using a host and a blue dye to obtain a filmnonuniformity of plusmn27 was successfully achieved Specif-ically the film was prepared using the solvent premixingdeposition method [16ndash19] The film was deposited shot byshot by using the planar source For each shot the precisedoping concentration with a favorable reproducibility wasobtained by controlling the amount of solvent-mixed preme-tered organic compounds To the moment no substantialresidual materials either single coating materials (HTL) ortwo materials (host and blue dye) were observed on theplanar source after evaporation This meant that most of theprepared solvent premixing materials including the dopant

and the host were successfully evaporated during the heat-ing process The conventional codeposition doping processrequires an extremely low deposition rate and a highlyprecise deposition-time control which is impractical andoccasionally impossible Insufficient doping or overdoping ofone or more of the dyes such as red or green dyes frequentlyoccurs explaining why numerous previously reported whiteOLEDs have failed to yield pure white emission [16]

33 Material Utilization Rate To measure the material uti-lization rate of the planar source plate directly (5 6 11 12)-tetraphenylnaphthacene (rubrene) was deposited onto theglass substrate at varying distances between the target sub-strate and planar source plate (TS) We used approximately16mg of rubrene for each studied material in the planarsource The weight difference of the planar source plate andglass substrate was measured as indicated in Table 3 [11]When the TS distance was 10 cm thematerial utilizationwasas high as 778 Based on the experimental results the TSdistance should be as short as possible to increase thematerialutilization rate in the deposition processes

A 778 material utilization rate was obtained using thenewly developed planar source which was much higherthan the 3 to 5 rate observed when using typical pointsources Improving material utilization by a wide marginshould decrease the manufacturing cost of mass production

34 Characterization of the Device We successfullyfabricated OLED devices by using the HTL deposited


35 4 45 5 55 6 65

Voltage (V)35 4 45 5 55 6 65

Voltage (V)

Lum

inan

ce (c

dm

2)

Luminance (cdm2)

5000

4000

3000

2000

1000

0

500040003000200010000

180

160

140

120

100

80

60

40

20

0

Curr

ent d

ensit

y (A

m2)

Device ADevice C

Device ADevice C

Device ADevice C

Device ADevice C

400 500 600 700 800

Wavelength (nm)

10

08

06

04

02

00

Nor

mal

ize i

nten

sity

40

35

30

25

20

15

10

Pow

er effi

cien

cy (l

mW

)

Device A(point)

Device C(point + planar)

Figure 11 The device performance compared with that of a device prepared using a complete conventional point source

using the proposed system equipped with a planar sourceplate and the other layers deposited using a conventionalsystem

Figure 9(a) presents the current density-voltage charac-teristic and Figure 9(b) presents the brightness-voltage char-acteristicThe current density was 31 Am2 and the brightnesswas 1000 cdm2 at an operation voltage of 485V Figure 9(c)presents the power efficiency versus luminance of the OLEDdevice The power efficiency at 1000 cdm2 is 211 lmW Thedevice also exhibits a color rendering index (CRI) of 70 at1000 cdm2 Figure 10 presents a photograph of the OLEDdevice illuminated at 35 V

Figure 11 presents the device performance compared withthat of a device prepared by using a complete conven-tional point sourceThe characteristics of luminance currentdensity and power efficiency achieved by partially usingthe proposed system equipped with a planar source werehigher than those achieved using a complete conventionalpoint source The wavelength spectra were similar in bothcases

4 Conclusion

A new system designed with a planar source is manufacturedfor OLED application A parallel DSMC method is used formodeling the process of organic material deposition of theplanar source system As the TS distance is decreased thefilm uniformity is higher and the material utilization rateis also higher much different from the point source basedevaporation system We can reduce the cost of the planarsource development and optimize the operating conditionsthrough accurate DSMC modeling Using such a planarsource has at least three advantages namely a high materialutilization rate high film uniformity and high degree ofdevice design freedom To the moment we successfullyachieved a layer with a host and a blue dye with a filmnonuniformity of plusmn27 Specifically the film was preparedusing the solvent premixing deposition method Moreoverby using the newly developed planar source a 778materialutilization rate was obtained which is much higher than the3 to 5 rate observed when using the typical point sourceThe system has enabled the organic thin films to be deposited


with a less than 5 nonuniformity and a material utilizationrate of over 70We successfully demonstrate the fabricationof anOLED device with the hole transporting layer depositedby the new systemwith the planar source and the other layersdeposited by the conventional system The power efficiencyof the OLED device is 211 lmW with a CRI of 70 at 1000cdm2 The evaporation system equipped by the novel planarsource can obtain large-area uniformity for thin-film evap-oration and high material utilization rate of various organicmaterials

Conflict of Interests

The authors declare that they have no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors acknowledge Professor Jong-Shinn Wu and hislaboratory team of the Department of Mechanical Engineer-ing National Chiao Tung University for assisting with theDSMC method This study was financially supported by theTaiwan Ministry of Economic Affairs through Grants nos102-EC-17-A-05-01-1111 D301AR3B00 and 102-EC-17-A-07-S1-181

References

[1] S Reineke F Lindner G Schwartz et al ldquoWhite organic light-emitting diodes with fluorescent tube efficiencyrdquo Nature vol459 no 7244 pp 234ndash238 2009

[2] S J Su E Gonmori H Sasabe and J Kido ldquoHighly efficientorganic blue-and white-light-emitting devices having a carrier-And exciton-confining structure for reduced efficiency roll-offrdquoAdvanced Materials vol 20 no 21 pp 4189ndash4194 2008

[3] T H Han Y Lee M R Choi et al ldquoExtremely efficient flexibleorganic light-emitting diodes with modified graphene anoderdquoNature Photonics vol 6 no 2 pp 105ndash110 2012

[4] C C Hwang ldquoPlane source and in-line deposition system forOLED manufacturingrdquo in Proceedings of the 44th InternationalSymposium Seminar and Exhibition (SID rsquo06) pp 1542ndash1545June 2006 Technical Papers 37

[5] H W Kim S Y Han H B Shim et al ldquoImprovement ofmaterial utilization of organic evaporation source for manu-facturing large-sized AMOLED devicesrdquo in Proceedings of theInternational Symposium Seminar and Exhibition (SID rsquo08) pp1450ndash1453 May 2008 Technical Papers 39

[6] G A Bird Molecular Gas Dynamics and the Direct Simulationof Gas Flows Clarendon Press Oxford UK 1994

[7] D M Mattox Handbook of Physical Vapor Deposition (PVD)Processing Noyes Westwood NJ USA 1998

[8] M Baldo M Deutsch P Burrows et al ldquoOrganic vapor phasedepositionrdquo Advanced Materials vol 10 no 18 pp 1505ndash15141998

[9] H Fukumoto Y Muramatsu T Yamamoto J YamaguchiK Itaka and H Koinuma ldquoCombinatorial physical vapordeposition of 120587-conjugated organic thin film librariesrdquo Macro-molecular Rapid Communications vol 25 no 1 pp 196ndash2032004

[10] H Usui ldquoFormation of polymer thin films and interface controlby physical vapor depositionrdquo in Proceedings of the SPIE vol7404 August 2009

[11] S-H Lai C-C Chen C-C Wang F-C Tung S-H Chenand Y-S Wang ldquoOLED deposition system using plane-sourceevaporation techniquesrdquo in Proceedings of the 20th InternationalDisplay Workshops (IDW rsquo13) 2013

[12] J-S Wu and Y-Y Lian ldquoParallel three-dimensional direct sim-ulation Monte Carlo method and its applicationsrdquo Computersand Fluids vol 32 no 8 pp 1133ndash1160 2003

[13] J S Wu and K C Tseng ldquoParallel DSMC method usingdynamic domain decompositionrdquo International Journal ForNumericalMethods in Engineering vol 63 no 1 pp 37ndash76 2005

[14] J-SWu K-C Tseng and F-YWu ldquoParallel three-dimensionalDSMC method using mesh refinement and variable time-stepschemerdquo Computer Physics Communications vol 162 no 3 pp166ndash187 2004

[15] C-C Su K-C Tseng H M Cave et al ldquoImplementation of atransient adaptive sub-cell module for the parallel DSMC codeusing unstructured gridsrdquoComputers amp Fluids vol 39 no 7 pp1136ndash1145 2010

[16] J H Jou Y S Chiu C P Wang R Y Wang and H-C HuldquoEfficient color-stable fluorescent white organic light-emittingdiodes with single emission layer by vapor deposition fromsolvent premixed deposition sourcerdquo Applied Physics Lettersvol 88 no 19 Article ID 193501 2006

[17] Y C Tsai and J H Jou ldquoLong-lifetime high-efficiency whiteorganic light-emitting diodes with mixed host composingdouble emission layersrdquo Applied Physics Letters vol 89 no 24Article ID 243521 2006

[18] J-H Jou C-Y Hsieh P-W Chen S Kumar and J H HongldquoCandlelight style organic light-emitting diode a plausiblyhuman-friendly safe night lightrdquo Journal of Photonics for Energyvol 4 no 1 Article ID 043598 2014

[19] J H Jou C P Wang M H Wu et al ldquoEfficient fluo-rescent white organic light-emitting diodes with blue-greenhost of di(4-fluorophenyl)amino-di(styryl)biphenylrdquo OrganicElectronics Physics Materials Applications vol 8 no 1 pp 29ndash36 2007

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Analytical ChemistryInternational Journal of


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Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


Substrate

Vapor flow

Organicmaterials

Evaporationsource plate

Heater

(a) (b)

Figure 1 Illustration of (a) the concept and (b) photograph of the novel evaporation system

Set initial state andread system data

Start

Move all molecules

Enter new molecules

Sort (index) molecules

Collide molecules

Sample flow field

Resetsampling data

Print out the data

Stop

Reach steady flow

Sufficientsampling

No

NoYes

Yes

(a) (b)

Figure 2 (a) Flow chart of the 3D DSMCmethod and (b) the 3D simulation cells

MEMSNEMS devices hypersonic flow analysis estima-tion of spacecraft and scramjet engines flow Impor-tantly it can also be adopted for modeling thin-filmdeposition process such as in the present case the physicalvapor evaporation of OLED to obtain high uniformity onlarge area-size substrates for mixed compounds with anydesignated concentration [7ndash10]

It is learned that via an accurate DSMC modelingthe development cost of the system can be tremendouslyreduced and the operational conditions of which can berapidly optimized It is also observed that the film uni-formity is greatly improved and material utilization rate ismarkedly enhanced as the target-to-source (TS) distance isdecreased


EML II (TPBi )

Cathode (LiFAl)

ETL (Bmpypb)

EML I (TcTa)

HTL (TAPC)

HIL (PEDOT PSS)

ITO glass


2 Experimental









Flux 119899 (m2sdots) 486119864 + 14


Number density 119899 (m3) 109119864 + 12



Mean free path 120582 150119864 + 02








Num

ber d

ensit

y (

m3)

79E + 16

53E + 16

36E + 16

24E + 16

16E + 16

11E + 16

73E + 15

49E + 15

33E + 15

22E + 15

15E + 15

10E + 15

(a)

64E + 16

44E + 16

30E + 16

21E + 16

14E + 16

96E + 15

66E + 15

45E + 15

31E + 15

21E + 15

15E + 15

10E + 15

Num

ber d

ensit

y (

m3)

(b)


35E minus 04

24E minus 04

16E minus 04

11E minus 04

75E minus 05

51E minus 05

34E minus 05

23E minus 05

16E minus 05

11E minus 05

74E minus 06

50E minus 06

Pres

sure

(Pa)

(a)

Pres

sure

(Pa)

26E minus 04

18E minus 04

13E minus 04

90E minus 05

63E minus 05

44E minus 05

30E minus 05

15E minus 05

10E minus 05

72E minus 06

50E minus 06

21E minus 05

(b)



0

10

20

30

40

50

60

70

80

90

100

10 20 30 60 90 120 150Gap distance (mm)


Uni

form

ity (

)m

ater

ial u

tiliz

atio

n effi

cien

cy (

)



Y

Z

X

18E minus 07

18E minus 07

17E minus 07

17E minus 07

16E minus 07

16E minus 07

15E minus 07

15E minus 07

Mas

s flux

(kg

m2

s)









14 142 47 33112 136 57 41910 54 42 778

1 2 3 4 5 6 7 8







119879 =1

119873

119873

sum

119894=1

119905119894

(1)

Δ119905 = radic1

119899 minus 1

119873

sum

119894=1

(119905119894minus 119879)

2 (2)

UN = Δ119905119879

times 100 (3)






2119879avgtimes 100 (4)



180

160

140

120

100

80

60

40

20

03 35 4 45 5 55 6 65

Voltage (V)

Curr

ent d

ensit

y (A

m2)

(a)

3 35 4 45 5 55 6 765

Volts (V)

Lum

inan

ce (c

dm

2)

5000

4000

3000

2000

1000

0

(b)

Luminance (cdm2)500040003000200010000

35

30

25

20

15

10

Pow

er effi

cien

cy (l

mW

)

(c)










35 4 45 5 55 6 65

Voltage (V)35 4 45 5 55 6 65

Voltage (V)

Lum

inan

ce (c

dm

2)

Luminance (cdm2)

5000

4000

3000

2000

1000

0

500040003000200010000

180

160

140

120

100

80

60

40

20

0

Curr

ent d

ensit

y (A

m2)

Device ADevice C

Device ADevice C

Device ADevice C

Device ADevice C

400 500 600 700 800

Wavelength (nm)

10

08

06

04

02

00

Nor

mal

ize i

nten

sity

40

35

30

25

20

15

10

Pow

er effi

cien

cy (l

mW

)

Device A(point)






4 Conclusion






Acknowledgments


References





























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


EML II (TPBi )

Cathode (LiFAl)

ETL (Bmpypb)

EML I (TcTa)

HTL (TAPC)

HIL (PEDOT PSS)

ITO glass


2 Experimental









Flux 119899 (m2sdots) 486119864 + 14


Number density 119899 (m3) 109119864 + 12



Mean free path 120582 150119864 + 02








Num

ber d

ensit

y (

m3)

79E + 16

53E + 16

36E + 16

24E + 16

16E + 16

11E + 16

73E + 15

49E + 15

33E + 15

22E + 15

15E + 15

10E + 15

(a)

64E + 16

44E + 16

30E + 16

21E + 16

14E + 16

96E + 15

66E + 15

45E + 15

31E + 15

21E + 15

15E + 15

10E + 15

Num

ber d

ensit

y (

m3)

(b)


35E minus 04

24E minus 04

16E minus 04

11E minus 04

75E minus 05

51E minus 05

34E minus 05

23E minus 05

16E minus 05

11E minus 05

74E minus 06

50E minus 06

Pres

sure

(Pa)

(a)

Pres

sure

(Pa)

26E minus 04

18E minus 04

13E minus 04

90E minus 05

63E minus 05

44E minus 05

30E minus 05

15E minus 05

10E minus 05

72E minus 06

50E minus 06

21E minus 05

(b)



0

10

20

30

40

50

60

70

80

90

100

10 20 30 60 90 120 150Gap distance (mm)


Uni

form

ity (

)m

ater

ial u

tiliz

atio

n effi

cien

cy (

)



Y

Z

X

18E minus 07

18E minus 07

17E minus 07

17E minus 07

16E minus 07

16E minus 07

15E minus 07

15E minus 07

Mas

s flux

(kg

m2

s)









14 142 47 33112 136 57 41910 54 42 778

1 2 3 4 5 6 7 8







119879 =1

119873

119873

sum

119894=1

119905119894

(1)

Δ119905 = radic1

119899 minus 1

119873

sum

119894=1

(119905119894minus 119879)

2 (2)

UN = Δ119905119879

times 100 (3)






2119879avgtimes 100 (4)



180

160

140

120

100

80

60

40

20

03 35 4 45 5 55 6 65

Voltage (V)

Curr

ent d

ensit

y (A

m2)

(a)

3 35 4 45 5 55 6 765

Volts (V)

Lum

inan

ce (c

dm

2)

5000

4000

3000

2000

1000

0

(b)

Luminance (cdm2)500040003000200010000

35

30

25

20

15

10

Pow

er effi

cien

cy (l

mW

)

(c)










35 4 45 5 55 6 65

Voltage (V)35 4 45 5 55 6 65

Voltage (V)

Lum

inan

ce (c

dm

2)

Luminance (cdm2)

5000

4000

3000

2000

1000

0

500040003000200010000

180

160

140

120

100

80

60

40

20

0

Curr

ent d

ensit

y (A

m2)

Device ADevice C

Device ADevice C

Device ADevice C

Device ADevice C

400 500 600 700 800

Wavelength (nm)

10

08

06

04

02

00

Nor

mal

ize i

nten

sity

40

35

30

25

20

15

10

Pow

er effi

cien

cy (l

mW

)

Device A(point)






4 Conclusion






Acknowledgments


References





























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


Num

ber d

ensit

y (

m3)

79E + 16

53E + 16

36E + 16

24E + 16

16E + 16

11E + 16

73E + 15

49E + 15

33E + 15

22E + 15

15E + 15

10E + 15

(a)

64E + 16

44E + 16

30E + 16

21E + 16

14E + 16

96E + 15

66E + 15

45E + 15

31E + 15

21E + 15

15E + 15

10E + 15

Num

ber d

ensit

y (

m3)

(b)


35E minus 04

24E minus 04

16E minus 04

11E minus 04

75E minus 05

51E minus 05

34E minus 05

23E minus 05

16E minus 05

11E minus 05

74E minus 06

50E minus 06

Pres

sure

(Pa)

(a)

Pres

sure

(Pa)

26E minus 04

18E minus 04

13E minus 04

90E minus 05

63E minus 05

44E minus 05

30E minus 05

15E minus 05

10E minus 05

72E minus 06

50E minus 06

21E minus 05

(b)



0

10

20

30

40

50

60

70

80

90

100

10 20 30 60 90 120 150Gap distance (mm)


Uni

form

ity (

)m

ater

ial u

tiliz

atio

n effi

cien

cy (

)



Y

Z

X

18E minus 07

18E minus 07

17E minus 07

17E minus 07

16E minus 07

16E minus 07

15E minus 07

15E minus 07

Mas

s flux

(kg

m2

s)









14 142 47 33112 136 57 41910 54 42 778

1 2 3 4 5 6 7 8







119879 =1

119873

119873

sum

119894=1

119905119894

(1)

Δ119905 = radic1

119899 minus 1

119873

sum

119894=1

(119905119894minus 119879)

2 (2)

UN = Δ119905119879

times 100 (3)






2119879avgtimes 100 (4)



180

160

140

120

100

80

60

40

20

03 35 4 45 5 55 6 65

Voltage (V)

Curr

ent d

ensit

y (A

m2)

(a)

3 35 4 45 5 55 6 765

Volts (V)

Lum

inan

ce (c

dm

2)

5000

4000

3000

2000

1000

0

(b)

Luminance (cdm2)500040003000200010000

35

30

25

20

15

10

Pow

er effi

cien

cy (l

mW

)

(c)










35 4 45 5 55 6 65

Voltage (V)35 4 45 5 55 6 65

Voltage (V)

Lum

inan

ce (c

dm

2)

Luminance (cdm2)

5000

4000

3000

2000

1000

0

500040003000200010000

180

160

140

120

100

80

60

40

20

0

Curr

ent d

ensit

y (A

m2)

Device ADevice C

Device ADevice C

Device ADevice C

Device ADevice C

400 500 600 700 800

Wavelength (nm)

10

08

06

04

02

00

Nor

mal

ize i

nten

sity

40

35

30

25

20

15

10

Pow

er effi

cien

cy (l

mW

)

Device A(point)






4 Conclusion






Acknowledgments


References





























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of







14 142 47 33112 136 57 41910 54 42 778

1 2 3 4 5 6 7 8







119879 =1

119873

119873

sum

119894=1

119905119894

(1)

Δ119905 = radic1

119899 minus 1

119873

sum

119894=1

(119905119894minus 119879)

2 (2)

UN = Δ119905119879

times 100 (3)






2119879avgtimes 100 (4)



180

160

140

120

100

80

60

40

20

03 35 4 45 5 55 6 65

Voltage (V)

Curr

ent d

ensit

y (A

m2)

(a)

3 35 4 45 5 55 6 765

Volts (V)

Lum

inan

ce (c

dm

2)

5000

4000

3000

2000

1000

0

(b)

Luminance (cdm2)500040003000200010000

35

30

25

20

15

10

Pow

er effi

cien

cy (l

mW

)

(c)










35 4 45 5 55 6 65

Voltage (V)35 4 45 5 55 6 65

Voltage (V)

Lum

inan

ce (c

dm

2)

Luminance (cdm2)

5000

4000

3000

2000

1000

0

500040003000200010000

180

160

140

120

100

80

60

40

20

0

Curr

ent d

ensit

y (A

m2)

Device ADevice C

Device ADevice C

Device ADevice C

Device ADevice C

400 500 600 700 800

Wavelength (nm)

10

08

06

04

02

00

Nor

mal

ize i

nten

sity

40

35

30

25

20

15

10

Pow

er effi

cien

cy (l

mW

)

Device A(point)






4 Conclusion






Acknowledgments


References





























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


180

160

140

120

100

80

60

40

20

03 35 4 45 5 55 6 65

Voltage (V)

Curr

ent d

ensit

y (A

m2)

(a)

3 35 4 45 5 55 6 765

Volts (V)

Lum

inan

ce (c

dm

2)

5000

4000

3000

2000

1000

0

(b)

Luminance (cdm2)500040003000200010000

35

30

25

20

15

10

Pow

er effi

cien

cy (l

mW

)

(c)










35 4 45 5 55 6 65

Voltage (V)35 4 45 5 55 6 65

Voltage (V)

Lum

inan

ce (c

dm

2)

Luminance (cdm2)

5000

4000

3000

2000

1000

0

500040003000200010000

180

160

140

120

100

80

60

40

20

0

Curr

ent d

ensit

y (A

m2)

Device ADevice C

Device ADevice C

Device ADevice C

Device ADevice C

400 500 600 700 800

Wavelength (nm)

10

08

06

04

02

00

Nor

mal

ize i

nten

sity

40

35

30

25

20

15

10

Pow

er effi

cien

cy (l

mW

)

Device A(point)






4 Conclusion






Acknowledgments


References





























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


35 4 45 5 55 6 65

Voltage (V)35 4 45 5 55 6 65

Voltage (V)

Lum

inan

ce (c

dm

2)

Luminance (cdm2)

5000

4000

3000

2000

1000

0

500040003000200010000

180

160

140

120

100

80

60

40

20

0

Curr

ent d

ensit

y (A

m2)

Device ADevice C

Device ADevice C

Device ADevice C

Device ADevice C

400 500 600 700 800

Wavelength (nm)

10

08

06

04

02

00

Nor

mal

ize i

nten

sity

40

35

30

25

20

15

10

Pow

er effi

cien

cy (l

mW

)

Device A(point)






4 Conclusion






Acknowledgments


References





























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of





Acknowledgments


References





























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of










Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

Research Article OLED Fabrication by Using a Novel Planar ...

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