Organic Light Emitting Devices
(OLEDs)
OLED is the acronym for Organic Light Emitting Diode
An OLED is a solid-state device composed of thin films of organic
molecules that create light when a current is applied
• Easily tunable emission color
• Amorphous materials (no need to match the
substrate’s lattice)
• Wide viewing angles
• Much faster response time (few microseconds
vs milliseconds)
• Low power consumption
• Self emitting. No need of backlight (so they are
lighter in weight and thinner)
• Flexible, high contrast, brighter
2
3
Dimensions: 7 mm2; 50 mm2; 100 mm2
Turn on voltages: 2.5 - 3.0 V
Luminance: 3000 cd/m2 @ 8 V
White light
Warm white
Cold white
4
5
1,0
0,8
0,8
EL Spectrum (a.u.)
1,0
0,6
0,4
Luminanza (9V)
0,2
300
400
500
600
700
0,6
0,4
Luminanza (9V)
0,2
2200 cd/m2
0,0
2500 cd/m2
0,0
300
800
400
500
600
700
800
Wavelength (nm)
Wavelength (nm)
0,50
Glass/ITO/PEDOT:PSS/NDP/EML/BCP/Alq3/Ca(Al)
0,45
Drogaggio EML 2%
Drogaggio EML 4%
0,40
EL Spectrum (a.u.)
EL Spectrum (a.u.)
ENEA OLEDs
Lunghezza d’onda
picchi emissione (nm)
0,35
0,30
0,25
0,20
0,15
0,10
0,05
0,00
-0,05
300
Picco 1
434
Picco 2
620
Picco 3
673
Luminanza (9V)
400
500
600
Wavelength (nm)
700
800
3500 cd/cm2
OLED’s Human-Friendly light quality has minimal health issues caused by artificial light
OLED
LED
intensity (%)
intensity (%)
wavelength(nm)
Side-effects of Artificial Light
• Blue Light Hazard
• Melatonin suppression
• Negative influence on
sleeping & health
LG CHEM.
wavelength(nm)
Natural and Human-Friendly Light
Qualities
Spectral Distribution and Color
Wavelengths with positive
characteristics from both a
psychological and physiological
perspective
LED applications in plant growth
The sun emits a full-spectrum white light, most of which is not used by plants.
Photosynthetically Active Radiation (PAR ) lays in the 400-700 nm wavelengths region.
An efficient lamp for crop artificial lighting should, therefore, convert electrical energy as much as
possible into PAR light
LED lights are more energy efficient
than incandescent. LED lights use only
2-17 watts of electricity, which is 25%80% less energy than standard lighting
systems.
LEDs offer more targeted wavelength
options. For example, for red and blue
selections.
LEDs last up to 10 times more than
compact fluorescent lamps, and far
longer than typical incandescent lights.
LED grow lights produce considerably
less heat than other lights, reducing the
need for cooling systems.
Advantages of OLED-based lighting in plant growing
applications
• Large and homogeneous emitting area.
• Single wavelength selection.
• Flexible solutions.
• Fitness to any kind of supports.
• Light weight and thinness.
• Low power consumption.
• No-heating effects.
• Environmental friendship (mercury-free, easy recycling).