Research On Novel Surface-conduction Electron-emission Display Cathodes

Aiming at stable and uniform electron emission for large-size flat panel display with independent intellectual property rights, four types of SED (Surface conduction Electron emission Display) cathode are realized, focusing on how to resolve the the VCNR (voltage controlled negative resistivity) effects of the device. For further, the gate controlled SED cathode is studied, which realizes the function of controlling conduction current and the function of electron emission at the same time.In order to form coplanar multi-layer composite thin film SED cathode, conductive thin film is deposited on nano islands surface; the nanoislands introduce thickness nonuniformity in so-formed multi-layer composite thin film. With current flowing through the composite thin film, some local gaps are formed in the composite film by current heating effect, and these gaps become emitting area. The focus is how to resolve VCNR effects of the device. By depositing composite thin film based on nano islands structure on the semiconductor layer, gate controlled SED cathode is formed. The gate voltage control the conduction current and electron emission function can be realized at the same time.In the study with SED cathode based on nano SnOx islands-C composite film, stable and uniform electron emission with emission efficiency of 1% with the anode voltage of 3kV is realized by introducing the structure of nano SnOx islands. The VCNR effect of the device is obvious because of the SnOx structure of lots of small islands among big islands. In the study with SED cathode based on nano C islands–C/W composite film, the structure of nano C islands is realized by etching C film using nano Bi islands as the mask; and during this etching process, lots of small islands are removed. The upper C/W compound thin film with good conductivity is deposited by doping W atom into amorphous C film. Stable and uniform electron emission is realized and the VCNR effect of the SED cathode is weakened. In the study with SED cathode based on nano C islands-Pd-C composite film, electron emission area of gaps withμm width is formed by introducing Pd layer; the VCNR effect is greatly weakened, so the characteristics of the SED cathode match with the MOSN-TFT well, and electron emission is stable and uniform with 1% efficiency at 3kV anode voltage. In the study with SED cathode based on nano Ag islands-C composite film, electron emission area of sub-micron width gap is formed by introducing the structure of nano Ag islands; the VCNR effect for the device characteristics is almost cleared and the working characteristics math with the MOSN-TFT well. Electron emission is stable and uniform with the efficiency of about 0.4% at the anode voltage of 3kV.In the study of gate controlled SED cathode, gate controlled SED cathode based on"InOx nano islands/C composite film- ZnO semiconductor layer"is brought forward and realized. Conduction current is controlled well by gate voltage and the electron emission can be controlled at the same time. Electron emission with efficiency of 0.1% can be realized at the anode voltage of 3kV and the on/off ration of conduction current is 1000:1.