Cesium mixtures and use thereof

Abstract

Cesium mixtures are produced based on the use of a mixture of at least one reducing agent and at least one cesium compound selected among molybdate, tungstate, niobate, tantalate, silicate and zirconate. The cesium mixtures are useful in the production of OLED-type screens.

We claim:  
     
         1 . A mixture of materials comprising at least one cesium compound and at least one reducing agent, wherein the cesium compound is selected from the group consisting of molybdate, tungstate, niobate, tantalate, silicate, and zirconate.  
     
     
         2 . The mixture according to  claim 1 , wherein the mixture comprises a single cesium compound and a single reducing agent.  
     
     
         3 . The mixture according to  claim 1 , wherein the reducing agent is selected from the group consisting of aluminum, silicon, zirconium, titanium, and alloys containing zirconium or titanium.  
     
     
         4 . The mixture according to  claim 3 , wherein the reducing agent comprises an alloy having a percent composition by weight Zr 84%-Al 16%.  
     
     
         5 . The mixture according to  claim 3 , wherein the reducing agent comprises an alloy having a percent composition by weight Zr 76.5%-Fe 23.5%.  
     
     
         6 . The mixture according to  claim 1 , wherein materials forming the mixture are in powder form.  
     
     
         7 . The mixture according to  claim 6 , wherein the powders comprise particles having a size smaller than 1 mm.  
     
     
         8 . The mixture according to  claim 7 , wherein the powders comprise particles having a size smaller than 500 μm.  
     
     
         9 . The mixture according to  claim 8 , wherein the powders comprise particles having a size between 10 and 125 μm.  
     
     
         10 . The mixture according to  claim 1 , wherein the weight ratio of the materials forming the mixture is from 10:1 to 1:10.  
     
     
         11 . A process for production of an OLED screen comprising a first transparent support, a first set of electrodes, an organic multilayer, a second set of electrodes and a second support, comprising the steps of: 
 introducing a cesium mixture according to  claim 1  into a chamber having a controlled atmosphere and means for heating the chamber;    arranging in the chamber a production intermediate of the OLED screen, the production intermediate being one obtained after having formed the organic multilayer;    causing vaporization of cesium from the mixture by heating the mixture; and    carrying out subsequent production steps of the OLED screen up to its sealing with the second support.    
     
     
         12 . The process according to  claim 11 , comprising the following series of operations: 
 producing the first set of electrodes on the first transparent support;    producing the organic multilayer on the first set of electrodes;    vaporizing cesium on the organic multilayer;    producing the second set of electrodes on the organic multilayer; and    sealing the first and second supports along their perimeters.    
     
     
         13 . The process according to  claim 11 , comprising the following series of operations: 
 producing the first set of electrodes on the first transparent support;    producing the organic multilayer on the first set of electrodes;    producing the second set of electrodes on the organic multilayer;    vaporizing cesium on the second set of electrodes; and    sealing the first and second supports along their perimeters.