Thin film and organic light-emitting device including the same

Patent metadata

Field	Value
Publication number	US-11713416-B2
Application number	US-202117220275-A
Country	US
Kind code	B2
Filing date	Apr 1, 2021
Priority date	Aug 27, 2015
Publication date	Aug 1, 2023
Grant date	Aug 1, 2023

Abstract

A thin film including a combination of a donor compound and an acceptor compound, and a phosphorescent dopant, wherein the donor compound and the acceptor compound form an exciplex having characteristics described in the specification.

First claim

What is claimed is:

1. A thin film comprising:
i) a combination of a donor compound and an acceptor compound, and

ii) an organometallic compound,
wherein the donor compound and the acceptor compound form an exciplex,
wherein a maximum emission wavelength λ max (Ex) in a photoluminescence spectrum of the exciplex is about 390 nanometers or greater and about 490 nanometers or less,
wherein a decay time T decay (Ex) of delayed fluorescence in a time-resolved photoluminescence spectrum of the exciplex is about 100 nanoseconds or greater,
wherein a ratio of a delayed fluorescence portion to the overall light-emitting portions in the time-resolved photoluminescence spectrum of the exciplex is about 10% or greater,
wherein a photoluminescence stability of the exciplex is 60% or greater,
wherein the photoluminescence spectrum and the time-resolved photoluminescence spectrum of the exciplex are each a spectrum measured at room temperature with respect to a film that is formed by co-deposition of the donor compound and the acceptor compound on a substrate, and
wherein photoluminescence stability of the exciplex is evaluated according to Equation 10:
PL stability (%)=( I 2 /I 1 )×100  Equation 10

wherein, in Equation 10,
I 1 is an intensity of a light at the maximum emission wavelength λ max (Ex) in a photoluminescence spectrum of Film 1, which is obtained immediately after formation of a film by co-deposition of the donor compound and the acceptor compound on a substrate, measured at room temperature in an inert atmosphere in which external air is excluded, and
I 2 is an intensity of a light at the maximum emission wavelength λ max (Ex) in a photoluminescence spectrum of Film 2, which is obtained after exposure of the Film 1 to pumping laser light used in the evaluation of I 1 in an inert atmosphere in which external air is excluded for 3 hours, measured at room temperature in an inert atmosphere in which external air is excluded.

2. The thin film of claim 1 , wherein the maximum emission wavelength λ max (Ex) is about 390 nanometers or greater and about 440 nanometers or less.

3. The thin film of claim 1 , wherein a decay time T decay (Ex) of delayed fluorescence in a time-resolved photoluminescence spectrum of the exciplex is about 100 nanoseconds to about 10 milliseconds.

4. The thin film of claim 1 , wherein a ratio of a delayed fluorescence portion to the overall light-emitting portions in the time-resolved photoluminescence spectrum of the exciplex is about 10% to about 65% or greater.

5. The thin film of claim 1 , wherein
an absolute value of the highest occupied molecular orbital energy level of the donor compound |HOMO (D)| is about 5.78 electron volts or less,
an absolute value of the lowest unoccupied molecular orbital energy level of the acceptor compound |LUMO (A)| is about 1.76 electron volts or greater,
the highest occupied molecular orbital energy level of the donor compound is calculated by using cyclic voltammetry, and
the lowest unoccupied molecular orbital energy level of the acceptor compound is calculated by using an ultraviolet absorption spectrum measured at room temperature.

6. The thin film of claim 1 , wherein
an absolute value of the highest occupied molecular orbital energy level difference between the acceptor compound and the donor compound |HOMO (A)−HOMO (D)| is about 0.037 electron volts or greater and about 1.1 electron volts or less,
an absolute value of the lowest unoccupied molecular orbital energy level difference between the acceptor compound and the donor compound |LUMO (A)−LUMO (D)| is about 0.001 electron volts or greater and about 1.1 electron volts or less,
the highest occupied molecular orbital energy level of the donor compound is calculated by using cyclic voltammetry, and
the lowest unoccupied molecular orbital energy level of the acceptor compound is calculated by using an ultraviolet absorption spectrum measured at room temperature.

7. The thin film of claim 1 , wherein
the acceptor compound comprises at least one electron-withdrawing group, and
wherein the electron-withdrawing group is selected from:
—F, —CFH 2 , —CF 2 H, —CF 3 , —CN, and —NO 2 ;
a C 1 -C 60 alkyl group substituted with at least one selected from —F, —CFH 2 , —CF 2 H, —CF 3 , —CN, and —NO 2 ;
a C 1 -C 60 heteroaryl group and a divalent non-aromatic condensed polycyclic heterocyclic group, each comprising *═N—*′ as a ring-forming moiety; and
a C 1 -C 60 heteroaryl group and a divalent non-aromatic condensed polycyclic heterocyclic group, each comprising *═N—*′ as a ring-forming moiety and each substituted with at least one selected from deuterium, —F, —CFH 2 , —CF 2 H, —CF 3 , —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C 1 -C 60 alkyl group, a substituted or unsubstituted C 2 -C 60 alkenyl group, a substituted or unsubstituted C 2 -C 60 alkynyl group, a substituted or unsubstituted C 1 -C 60 alkoxy group, a substituted or unsubstituted C 3 -C 10 cycloalkyl group, a substituted or unsubstituted C 1 -C 10 heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10 cycloalkenyl group, a substituted or unsubstituted C 1 -C 10 heterocycloalkenyl group, a substituted or unsubstituted C 6 -C 60 aryl group, a substituted or unsubstituted C 6 -C 60 aryloxy group, a substituted or unsubstituted C 6 -C 60 arylthio group, a substituted or unsubstituted C 7 -C 60 arylalkyl group, a substituted or unsubstituted C 1 -C 60 heteroaryl group, a substituted or unsubstituted C 1 -C 60 heteroaryloxy group, a substituted or unsubstituted C 1 -C 60 heteroarylthio group, a substituted or unsubstituted C 2 -C 60 heteroarylalkyl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.

8. The thin film of claim 7 , wherein
the donor compound is selected from a compound represented by Formula D-1, and
the acceptor compound is selected from compounds represented by Formulae A-1 and A-2:
Ar 1 -(L 1 ) a1 -Ar 2   Formula D-1

Ar 11 -(L 11 ) a11 -Ar 12   Formula A-1

Formula A-2

wherein, in Formulae D-1, A-1, A-2, and 11 to 14,
Ar 1 is selected from groups represented by Formulae 11 and 12,
Ar 2 is selected from:
groups represented by Formulae 11 and 12, a phenyl group, a naphthyl group, and a benzimidazolyl group; and
a phenyl group, a naphthyl group, and a benzimidazolyl group, each substituted with at least one selected from deuterium, a hydroxyl group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C 1 -C 20 alkyl group, a C 1 -C 20 alkoxy group, a phenyl group, a naphthyl group, a fluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,
Ar 11 and Ar 12 are each independently selected from groups represented by Formulae 13 and 14,
X 1 is N or C(T 14 ), X 2 is N or C(T 15 ), and X 3 is N or C(T 16 ), wherein at least one selected from X 1 to X 3 is N,
L 1 is selected from:
a single bond, a phenylene group, a naphthylene group, a fluorenylene group, a carbazolylene group, a dibenzofuranylene group, and a dibenzothiop

Assignees

• Samsung Electronics Co Ltd
• Samsung Sdi Co Ltd

Inventors

• Ihn Sooghang
• Huh Dalho
• Lee Namheon
• Son Jhunmo
• Kang Hosuk
• Kim Sangmo
• Kim Jongsoo
• Kim Joonghyuk
• Kim Hyunjung
• Son Youngmok
• Sim Myungsun
• Chung Yeonsook
• Park Youngseok
• Jung Yongsik

Classifications

• C09K11/06 Primary

  containing organic luminescent materials · CPC title

• C09K11/02

  Use of particular materials as binders, particle coatings or suspension media therefor · CPC title

• H05B33/14

  characterised by the chemical or physical composition or the arrangement of the electroluminescent material {, or by the simultaneous addition of the electroluminescent material in or onto the light source} · CPC title

• C09K2211/1007

  Non-condensed systems · CPC title

• C09K2211/1011

  Condensed systems · CPC title