Radiance-voltage characteristics

Figure 13-3. Typical currcm-voliagc and radiance-voltage characteristics of an MEH-PPV-based 01.MJ with an Au anode and an IIO cathode.

There have been numerous studies of the electrical and emission properties of conjugated polymer-, small molecule-, and molecularly doped polymer-based OLEDs. The current-voltage and radiance-voltage characteristics have been nica sured as a function of thickness of the organic layer, temperature, different metal electrodes, etc. in an attempt to understand the device physics. A major factor in hibiting progress is the purity of the organic impurities that are incorporated dur-... 

The measure of the voltage has to be made with a connection veiy close to the useful part of the filament. When the cmcible contains melted tin, its resistance is changed and the calculation of temperatnre using this method becomes impossible. However, we can assume by primary approximation that the characteristic P=f (T) does not vary mnch. Indeed, at the pressure present, the heat is mainly dissipated by radiance and the emitting area is about the same size whether the tin is inside the cmcible or not. 

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