Current density—voltage—luminance

FIGURE 6.18 Current density-voltage, luminance-voltage, and luminous efficiency-voltage characteristics measured for the OLEDs made with an AZO anode and an ITO anode. 

Figure 7.6 shows typcial current density-voltage-luminance (J-V-L) and emission characteristics of an OLED device. OLEDs have a similar electrical characteristic to that of a rectifying diode. In forward bias, the device starts with a small current at low voltages. In this region, charge carriers are injected into the device but little exciton formation, hence light... 

Before ending this section, the current density-voltage-luminance characteristics of two PLEDs using Ag/Ca (solid symbol) and Ag/Al/CsF (open symbol) as a cathode, respectively, with 40 nm of poly(3,4-ethylene dioxythiophene) (PEDOT) polystyrene sulfonate) (PSS) as a polymer anode and 100 nm of F8BTas a green-emitting layer are depicted in Fig. 5.16. The thickness of the Ca, CsF, A1 and Ag layers is 50, 5, 80 and 100 nm, respectively. The Al/CsF instead of Cs was used as the cathode since the role of A1 on CsF is known to release Cs into the polymer [80], It can be seen that the Ca device shows much larger current density than the CsF/Al device, in contrast to the common belief that the lower work function of... 

Figure 14.21 Eleotroluminesoenoe chemistry and spectrum (top) and (bottom) current density ( ) voltage-luminance (O) characteristics for indium-tin oxide/polymer 3 (above).

FIGURE 6.12 (a) Current density-voltage and (b) luminance-current density characteristics of OLEDs with a configuration of ITO/Alq3 interlayer/NPB/Alq3/Ca/Ag. The thickness of the Alq3 interlayer was varied over a range of 0-5.0 nm. 

Fig. 9. EL spectrum of device with dLip 5nm (left) (inset image of a large area device) Luminance-current density-voltage characteristics (right).

Fig. 21 Top normalized electroluminescence spectra for (dotted line) 30, (dashed line) [Pt(C1 ANAN)(C CC6H4Me-4)], and (continuous line) 40 at 4% doping level and multilayer configuration of device. Bottom current density, voltage and luminance characteristics (inset luminescent efficiency vs current density) for OLED using 30 as emitter as 4% doping level (Reproduced with permission from [36a]. Copyright 2002 Royal Society of Chemistry)...

Fig. 4.13. Comparison of pLED on conventional ITO-coated glass substrate with pLED on ITO-free PET substrate, (a) Current density-voltage characteristics, (b) Luminance-voltage characteristics...

Figure 6. Luminance-voltage, current density-voltage characteristics of o-Mc PTPDMA (200A) / Alq (70GA) devices.

Figure 7 Changes in the current density and luminance with the appHed voltage in a multilayer LED of 3 with an ITO/3 PVK(l 4 w/w)/BCP/Alq3/LiF/Al device configuration. Inset EL spectrum.

Figure 16-42. Semi log ploi of current density (0) and luminance (O) of an ITO/Oocl-OPV5 (ISO nm)/Oocl-OPV5-CN" (45 nm)/AI double-layer device as a function of bias voltage. Inset double-layer electroluminescence spectrum.

Excellent electron-transporting properties of quinoxaline (also demonstrated for noncon-jugated quinoxaline-containing polymer 588 [684] and quinoxaline-based polyether 589 [685]) resulted in a substantially decreased turn-on voltage of PPV/590 PLED (3.6 V), which is much lower than that of pure PPV in the same conditions (7 V). These diodes showed a maximum luminance of 710 cd/m2 (ca. 40 times brighter than the PPV diode at the same current density and voltage) [686]. 

FIGURE 6.9 Current density vs. bias voltage (a) and luminance vs. current density (b) characteristics of identical devices made on ITO anodes treated under different oxygen plasma conditions. 

Operating Voltage and Corresponding Luminous Efficiency of Identical OLEDs Made on ITO Anode with Different Alq3 Modification Layer Thicknesses, Measured at a Current Density of 100 mA/cm2... 

FIGURE 7.6 Typical current density (filled squaresj-voltage-luminance (open squares) (J-V-L) and emission characteristics (inset figure) of an OLED device. This J-V-L data is from the device discussed later in Figure 7.10. 

Fig. 9.13. Luminous efficiencies for the UDC The inset shows almost identical current PhOLED deposited by OVPD (circles) and VTE density-voltage characteristics of the (squares). The VTE device reaches a maximum PhOLED deposited by OVPD and VTE. efficiency of 24 cd A-1 whereas that for the (Figure courtesy of UDC.)...

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