*4.5.1. Original type FEOLEDS*

As shown in Fig. 7 (a), FEOLEDs (original type) are similar to FEDs, but they use organic light emitting material instead of a phosphor. In these FEOLEDs an ITO film is used as anode and CNTs template as cathode. By applying the driving voltage to both the electrodes (ITO and CNTs template), then electrons and holes move toward the interface between the two transport layers (HTL, and ETL) and recombine to form excitons. Finally, these excitons emit light through the ITO substrate..

Field Emission Organic Light Emitting Diode 33

and holes, 4) migration singlet excitons to organic emitting layer and 5) radiative

**Figure 9.** (a) Structure of a FEOLED with Hole blocking layer and (b) emission of blue light.

As shown in Fig. 10, the typical structure of FEOLEDs in this work comprises a CNTs template cathode and the strip electron multiplier formed on an OLED as a part of anode. It

In this section, the current density (J)-applied voltage (V) characteristics and the optical performances of a FEOLED with the strip electron multiplier are studied experimentally.

Fig.10 shows the configuration of FEOLED in this work, where the upper portion is an OLED lower part is the external electron source of CNTs cathode. The Soled switch is use to control

OLED and Sext switch is used to control the external electron source of CNTs template.

**Figure 10.** Schematic presentation of an apparatus for characterizing a FEOLED with strip electron

**4.6. A FEOLED with strip electron multiplier** 

can be assembled in a vacuum chamber.

*4.6.1. Experimental* 

multiplier

recombination of single excitons.
