ORGANIC EL ELEMENT AND ITS METHOD OF DRIVING

• Main Author: TSURUOKA YOSHIHISA
• Format: Patent
• Language: English
• Published: 27.04.2001
• Edition: 7
• Subjects: ADVERTISING; ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICESUSING STATIC MEANS TO PRESENT VARIABLE INFORMATION; BASIC ELECTRIC ELEMENTS; CRYPTOGRAPHY; DISPLAY; EDUCATION; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; PHYSICS; SEALS; SEMICONDUCTOR DEVICES

PROBLEM TO BE SOLVED: To make an emission color change in accordance with the change of ambient temperature for displaying. SOLUTION: The organic EL element 1a has a layer structure consisting of organic luminescent layer 2 and negative electrode 4. The organic luminescent layer 2 is formed by positive electrode 3 which is composed by ITO of transparent and conductive film deposited on the glass substrate 5 or the like, and hole conductive luminescent layer 2a which is composed by PVCz doped with 0.5-5 weight % of perylene forming the hole conductive layer, and electron conductive luminescent layer 2b which is composed by Alq3 doped with 5-30 weight % of DCM forming the electron conducting layer. The negative electrode 4, composed of metals with small work function such as Mg:Ag, Al:Li, LiF+Al and the like, is formed on the organic luminescent layer 2. The organic EL element changes its luminous color of organic luminescent layer 3 in accordance with the change of the ambient temperature, by constant current operation of 100 mA/cm2 with voltage applied between positive electrode 3 as plus and negative electrode 4.