Method for producing organic light-emitting element, organic display panel, organic light-emitting device, method for forming functional layer, ink, substrate, organic light-emitting element, organic display device, and inkjet device

A method of forming a functional layer, comprising:

• preparing ink including functional material as a material for the functional layer and a solvent dissolving the functional material, and filling an inkjet device having an ink ejection nozzle with the ink, the functional material having a weight-average molecular weight equal to or greater than 340,000 and equal to or less than 400,000;
• preparing a substrate on which the functional layer is to be formed;
• positioning the inkjet device above the substrate, and causing the inkjet device to eject a drop of the ink onto the substrate;
• and
• forming the functional layer by drying the ink ejected onto the substrate;
• and, wherein
• in the preparation of the ink, when a value Z denotes a reciprocal of the Ohnesorge number Oh determined by density ρ (g/m3), surface tension γ (mN·m), and viscosity η (mPa·s) of the ink and a diameter r (mm) of the ink ejection nozzle, the value Z is within a range of Formula 1,
• in the ejection of the drop of the ink, speed V (m/s) of the ejected drop of the ink is within a range of Formula 2, and
• the value Z and the speed V (m/s) satisfy Formula 3:
• 3≦Z≦30
• where Z=1/Ohnesorge number Oh=(r·ρ·γ)1/2/η) (Formula 1);
• 3≦V≦6 (Formula 2);
• and
• V≦−0.95 Ln(Z)+7.63 (Formula 3).

An ink that is ejected onto a substrate by an inkjet device having an ink ejection nozzle, and is dried to form a functional layer, comprising:

• functional material as a material for the functional layer, the functional material having a weight-average molecular weight equal to or greater than 340,000 and equal to or less than 400,000;
• and
• a solvent dissolving the functional material, wherein
• when a value Z denotes a reciprocal of the Ohnesorge number Oh determined by density ρ (g/m3), surface tension γ (mN·m), and viscosity η (mPa·s) of the ink and a diameter r (mm) of the ink ejection nozzle, the value Z is within a range of Formula 1,
• speed V (m/s) at which the ink is ejected is within a range of Formula 2, and
• the value Z and the speed V (m/s) satisfy Formula 3:
• 3≦Z≦30
• where Z=1/Ohnesorge number Oh=(r·ρ·γ)1/2/η (Formula 1);
• 3≦V≦6 (Formula 2);
• and
• V≦−0.95 Ln(Z)+7.63 (Formula 3).

An inkjet device that is for containing therein ink including functional material as a material for a functional layer and a solvent dissolving the functional material, and ejects the ink from an ink ejection nozzle onto a substrate to form the functional layer, the functional material having a weight-average molecular weight equal to or greater than 340,000 and equal to or less than 400,000, wherein

• when a value Z denotes a reciprocal of the Ohnesorge number Oh determined by density ρ (g/m3), surface tension γ (mN·m), and viscosity η (mPa·s) of the ink and a diameter r (mm) of the ink ejection nozzle, the value Z is within a range of Formula 1,
• speed V (m/s) at which the ink is ejected is within a range of Formula 2, and
• the value Z and the speed V (m/s) satisfy Formula 3:
• 3≦Z≦30
• where Z=1/Ohnesorge number Oh=(r·ρ·γ)1/2/η (Formula 1);
• 3≦V≦6 (Formula 2);
• and
• V≦−0.95 Ln(Z)+7.63 (Formula 3).