Printing ink and electronic device

1. A printing ink, comprising: an inorganic nano-material and at least one ester-based organic solvent; wherein:

the inorganic nano-material comprises at least one luminescent quantum dot material, the at least one luminescent quantum dot material having a monodisperse size distribution and at least one shape selected from the group consisting of: a spherical shape, a cubic shape, a rod shape, and a branched structure; and

the ester-based organic solvent has a boiling point ≥200° C., and a viscosity in a range of 1 cPs to 100 cPs at 25° C., the ester-based organic solvent is able to be evaporated from a solvent system and form an inorganic nano-material film.

2. The printing ink according to claim 1 , wherein the ester-based organic solvent has a surface tension in a range of 19 dyne/cm to 50 dyne/cm at 25° C.

3. The printing ink according to claim 1 , wherein the ester-based organic solvent has a structure shown as a general formula (I), (II) or (III):

wherein, R 1 to R 6 may be identical or different, being a linear alkyl, alkoxy or thioalkoxy group having 1 to 20 Carbon atoms, or a branched or cyclic alkyl, alkoxy or thioalkoxy group or a silyl group having 3 to 20 Carbon atoms, or a substituted keto group having 1 to 20 Carbon atoms, an alkoxycarbonyl group having 2 to 20 Carbon atoms, an aryloxycarbonyl group having 7 to 20 Carbon atom, a cyano group (—CN), a carbamoyl group (—C(═O)NH2), a haloformyl group (—C(═O)—X, wherein X represents a halogen atom), a formyl group (—C(═O)—H), an isocyano group, an isocyanate group, a thiocyanate group or an isothiocyanate group, a hydroxyl group, a nitro group, a CF3 group, a Cl, a Br, an F, a crosslinkable group or a substituted or unsubstituted aromatic or heteroaromatic ring system having 5 to 40 ring atoms, or an aryloxy or a heteroaryloxy group having 5 to 40 ring atoms, or a combination thereof.

4. The printing ink according to claim 1 , wherein a luminescence wavelength of the at least one luminescent quantum dot material is between 380 nm and 2500 nm.

5. The printing ink according to claim 1 , wherein the inorganic nano-material is a binary or multiple semiconductor compound quantum dots or a mixture thereof, in a group IV, a group II-VI, a group II-V, a group III-V, a group III-VI, a group IV-VI, a group I-III-VI, a group II-IV-VI, a group II-IV-V of a Periodic Table.

6. The printing ink according to claim 1 , further comprises at least one organic functional material, wherein the organic functional material is selected from: a hole injection material (HIM), a hole transport material (HTM), an electron transport material (ETM), an electron injection material (EIM), an electrons barrier material (EBM), a hole blocking material (HBM), a light emitter (Emitter), and a host material (Host).

7. The printing ink according to claim 1 , wherein a weight ratio of the inorganic nano-material is from 0.3% to 70%, and a weight ratio of the ester-based organic solvent is from 30% to 99.7%.

8. The printing ink according to claim 1 , wherein the ester-based organic solvent is selected from an_octanoic acid alkyl ester, an alkyl ester sebacate, an alkyl ester stearate, an alkyl ester benzoate, an alkyl ester phenylacetate, an alkyl ester cinnamate, an alkyl ester oxalate, an alkyl ester_maleate, an alkyl ester lactone, an alkyl ester oleate, or a mixture of at least two thereof.

9. The printing ink according to claim 8 , wherein the ester-based organic solvent is selected from or mainly selected from an octyl octanoate, a diethyl sebacate or a mixture thereof.

10. The printing ink according to claim 9 , wherein the ester-based organic solvent further comprises at least one other ester, the other ester comprises a diallyl phthalate, an isononyl isononanoate, or a mixture thereof, a total weight of the other ester in the ester solvent is less than 50%.