SUN Yuan-yuan, HUA Yu-lin, ZHENG Jia-jin, YIN Shou-gen, FENG Xiu-lan, WANG Shu-guo. Fabrication and Study of Flexible Organic White-light-emitting Devices[J]. Chinese Journal of Luminescence, 2005,26(3): 327-332
SUN Yuan-yuan, HUA Yu-lin, ZHENG Jia-jin, YIN Shou-gen, FENG Xiu-lan, WANG Shu-guo. Fabrication and Study of Flexible Organic White-light-emitting Devices[J]. Chinese Journal of Luminescence, 2005,26(3): 327-332DOI:
Organic light emitting devices (OLED) has gained a rapid development recently. It is technically crucial in the field of plate panel displays in the future. The most important superiority of OLED is that it can realize flexible displays-flexible organic light emitting devices(FOLED). White light
which is composed of three discrete peaks in R/G/B regions
is very important and particularly useful for full-color display. However
most of white OLEDs
so far
are fabricated with multilayer structures
which results in the complication of fabrication process and decline of quantum efficiency. So these devices are not suitable for the purpose of large-scale industrial manufacture.Bis-2-(2-hydroxyphenyl)benzothiazolate zinc (Zn(BTZ)
2
) is one of the best organic electroluminescent materials used for white light-emitting devices (OLED). PET slice with ITO is used as substrate of FOLED. We use Zn(BTZ)
2
as main light-emitting material and fabricate a new type of flexible organic white-light-emitting devices. The configurations of the devices are as follows:PET/ITO/PVK:TPD/Zn(BTZ)
2
/Al. The bright and steady light emitting has been obtained
and the brightness of the devices comes to 1000 cd/m
2
(at a driving voltage of 25 V). We also measure the CIE coordinates of the above devices
which are (
x
=0.242
y
=0.359)
and corresponding quantum efficiency value is 0.30%. Then the Rubrene is doped in Zn(BTZ)
2
and the configurations of this devices are as follows:PET/ITO/PVK:TPD/Zn(BTZ)
2
/Al and ITO/PVK:TPD/Zn(BTZ)
2
:Rubrene/Al. The brightness of the devices comes to 1200 cd/m
2
(at a driving voltage of 25 V)
and the CIE coordinates of the above devices are (
x
=0.339
y
=0.339)
and corresponding quantum efficiency value is 0.35%. Details on the white-light-emitting characteristics of the devices are explained by the diagram of current density-voltage
optical current-voltage and quantum efficiency-current density
which are measured using Keithley 485 Picoammeter and 2400 SourceMeter. Last
we also discuss the emitting mechanism of the material and the devices.