Tungsten Trioxide Conductive Thin Film Electrode Preparation by Hot Steaming

Conductive thin film electrodes are the basic components of organic light-emitting devices (OLED). Their performance directly affects the light-emitting efficiency of the whole device. Among them, transparent conductive film is a photoelectric material which combines optical transparency and conductivity. Because of its excellent photoelectric properties, transparent conductive film can be widely used in solar cells, LED, TFT, LCD and touch screen display fields.

Some enterprises adopt an organic electroluminescent device, which includes stacked anodes, luminescent layers and cathodes. Among them, the anode consists of successive layers of substrate, silver layer and tungsten trioxide layer. The silver layer is made of silver nanowires with diameters of 50-500 nm, and tungsten trioxide layer is made of nanowires with diameters of 8-80 nm.

In light emitting devices, silver and tungsten trioxide layers are prepared by hot-evaporation process.

1.Substrates are acid treated, followed by ultrasonic cleaning with acetone and ethanol. After drying, the substrates are placed in the quartz tubes of the tubular furnace. The vacuum degree of the quartz tubes of the tubular furnace is 102 Pa~103Pa, and the temperature is 350~700 ℃. Then the inert gas is injected into the quartz tubes of the tubular furnace. The flow velocity of the inert gas is 50 cm3/min~180 cm³/min.

2.Place silver powder in a boat and place the boat in a quartz tube of a tubular furnace. The evaporation time of the silver powder is 10 minutes to 40 minutes, forming a silver layer on the surface of the substrate and stopping evaporation of the silver layer.

3.Place the tungsten trioxide powder in the boat and place the boat in the quartz tube of the tubular furnace; the evaporation time of the tungsten trioxide powder is 3 minutes to 20 minutes, the tungsten trioxide layer is formed on the silver layer surface, the evaporation plating of the tungsten trioxide layer is stopped, and the inert gas is cooled to room temperature; and peel off the substrate to obtain the stacked silver layer and the tungsten trioxide conductive thin film. Membrane electrode.

The conductive thin films are prepared by depositing tungsten trioxide thin films on the surface of silver layer. The conductive thin films are assembled into nanowires, which have high surface work function and can ensure high light transmittance. The conductive thin films have high visible light transmittance of 88%~90% in the long range of 470~790 nm, block resistance of 15~85/, and surface work function of 4.8~5.1eV. When the conductive film is used as the anode of organic light-emitting devices, the difference between the surface work function of the conductive film and the HOMO level of the general organic light-emitting layer is small, which reduces the carrier injection barrier and significantly improves the luminescence efficiency.

• < Prev
• Next >