PROGRESS OF OLED TECHNOLOGY FOR LIGHTING

Transcription

1 PROGRESS OF OLED TECHNOLOGY FOR LIGHTING M. Anandan (SID) Organic Lighting Technologies LLC Austin Texas 1

2 OLED LAMPS 2

3 OLED: LIGHT GENERATION 3

4 OLED: FLUORESCENT 4

5 OLED: PHOSPHORESCENT 5

6 THREE FAMILIES OF OLED 6

7 OLED LIGHTING vs ILLUMINATION ENGG-PRACTICE OLED-lighting practice Luminance : cd/m 2 Life performance: 50% depreciation Efficiency quoted at 1000 cd/m 2 (40 lumens) Illumination Engg practice Luminous flux: Lumens Life performance: 30% depreciation Efficiency quoted at high flux levels: 400 lumens (10,000 cd/m 2 ) 7 Peter Alevermore et.al- Highly efficient Lighting, SID-10 Digest, pp

8 HIGH INTENSITY - Parameter CFL Linear FL LED OLED Luminance 47,700 cd/m 2 (GE, 75W, 6500K, x = 0.309; y = 0.344) 3890 (GE, 40W, x = 0.380; y = 0.393) 1000,000 (Nichia white; x = 0.307; y = 0.315; NS2W123BT) 1000 (x = 0.448; y = 0.435) 8

9 Parameter LED: THE KING Luminous Flux (Lumen) 1000 (2275-latest) Luminous efficiency (lm/w) LED: The King * OLED CRI Life (hours) 50,000 (L70) At 1000 lm 10,000 (L70) at 40 lm * Cree: LR6-DR1000; 1-UDC s paper:peter A Levermore et.al- Highly Eff..Solid state lighting, SID-2010 Digest 9

10 ANATOMY OF LED LAMP 10

11 OLED: LAMP ADVANTAGES Planar light source Printable process (and hence low cost) Flexible light source Transparent light source Less costly fixtures and heat sink (if needed) When will all these be realized?? 11

12 OLED: LIFE PERFORMANCE (All Fluorescent) 12 John Hamer et.al System design for a wide color gamut TV sized AMOLED display, Journal of the SID 16/1, 2008, pp.3-14

13 WHITE OLED: ALL FLUORESCENT Known for long life at high current density (20 ma/cm 2 ) All colors including Blue is more stable and Blue has longer life than phosphorescent blue Efficiency is low-triplet transition forbidden (25 lm/w at 1000 cd/m 2 ) 13

14 PHOSPHORESCENT BLUE Debatable for long-term life performance 100% phosphorescent OLEDs (RGB phos materials) for high intensity of light is not embraced by the industry for mass mfg. The life performance of Phos Blue has shown remarkable improvement but not as good as fluorescent blue and not used in commercial product. 14

15 WHITE OLED: ALL PHOSPHORESCENT High efficiency 4x compared to Fluorescent white Short Life of blue in the mix degrades the color stability as the OLED ages High light output shortens the life of White OLED Efficiency dip takes place at high light output. 15

16 HYBRID WHITE OLED: FLUORESCENT BLUE AND PHOS RED AND GREEN Best of both worlds Good color stability because of stable fluorescent blue Efficiency advantage because of phos red and green Blue is inefficient- triplets transition forbidden 16

17 HYBRID WHITE OLED: FLUORESCENT BLUE AND PHOS RED AND GREEN 17

18 WHITE OLED: FLUORESCENT PUMPED PHOLED (FP-PHOLED) Triplets on Fluorescent blue is employed to pump phos orange and thus triplets of fluor blue are utilized Good color stability in life Efficiency nearly equal to all PHOLED white Long life Reduced efficiency dip (droop, roll-off) 18

19 FP-PHOLED Thickness of Orange emitter: 20 nm Thickness of green emitter: 10 nm Thickness of Blue emitter: 15 nm CRI: 86 (at 1000 cd/m 2 ) Lumin Eff: 85.5 lm/w-with light extraction- (not in the reference below) Thickness, doping are all optimized for efficiency and chromaticity Gregor Schwartz et.al- Harvesting triplet excitons Diodes, Adv. Mater 19, ,

20 FP-PHOLED: Energy Level Diagram 20

21 EFFICIENCY DIP IN FP-PHOLED 21

22 EFFICIENCY DIP : LED COMPARISON 22

23 EFFICIENCY COMPARISON 23 With and without light extraction, lm/w will differ for different work by authors

24 DOE (USA) ENERGY STAR CATEGORY A CRI: 80 Criterion Efficiency: >35 lm/w Luminous flux: > 200 lumens (Surface mounted) Life: 25,000 hours (L70) 24

25 SINGLE OLED LAMP 9.6 X 11.6 (NON-TILED) AUO demonstration at FPDI 2010: Efficiency (at 1500 cd/m 2 ) : 50 lm/w CRI: 80 CCT: 3000 K Hybrid OLED Life:??? 25

26 ORBEOS: OSRAM OLED LAMP Glass Diameter: 88 mm Thickness: 2.1 mm Weight: 24 g Efficiency: 25 lm/w Luminance: 1000 cd/m 2 Life: 5000 hrs Price: $375 26

27 LUMIBLADE: PHILIPS OLED Product performance (2009) Luminance: 1000 cd/m Efficiency: 20 lm/w LAMP Life: 10,000 hours (at 50% initial brightness) Thickness: 1.8 mm Area: 70 mm x 70 mm Price: $270 (As a rule of thumb: we expect the efficiency to double every 2-3 years) 27

28 PRINTED OLED: PANASONIC (2009 March) Luminance: 1000 cd/m 2 Efficiency: 40 lm/w CRI: 95 Life: 20,000 hrs Mass Manufacturing in

29 LG CHEM: OLED LAMP Luminance: 1000 cd/m2 Efficiency: lm/w CCT: K Sizes: 50 x 70 mm; 150 x 20 mm; 150 x 30 mm; 150 x 150 mm Mass mfg: 2H-2010 Red and green: Phos Blue: Fluor 29

30 RHOM: OLED LAMP 2011 Luminance: 1000 cd/m 2 Size: 145 mm x 145 mm Efficiency: lm/w Thickness: 4.1 mm Red: Phos; Blue and Green: Fluor 30

31 UNIVERSAL DISPLAY CORPORATION: OLED LAMP 2010 Size: 150 x 150 mm Luminance: 1000 cd/m 2 CRI: 87 CCT: 3055K Efficiency: 50 lm/w Life to 70% level: 10,000 hrs Small pixel: Eff: 109 lm/w; CRI: 80; Life (70%): 15,000 hrs; Luminance: 1000 cd/m 2 ; CCT: 3295 K 31

32 COLOR TUNABLE OLED LAMP Verbatim company (Joint-Mitsubishi, Pioneer) Size: Size: 14cmx14cm Efficiency (typical): 28lm/w Types of materials: small molecular OLED (as emitter) Partially using solution OLED, color RGB color tunable-temperature tunable(2700k-6500k) Lifetime(LT70, typical): 8000hrs CRI (typical): 80 Manufacturing:

33 CONCLUSION OLED research should concentrate on FP- PHOLED for Lighting Application Good Color stability, long life, high efficiency and reduced efficiency dip BEST OF ALL WORLDS exist in FP-PHOLED. The mechanism of triplet-triplet annihilation should be investigated in detail to solve the problem of efficiency dip. Plenty of lessons available from inorganic LEDs to solve efficiency dip problem- notable are (i) Charge overflow at high current densities (ii) Auger emission losses at high current densities. 33