Electroluminescent device

• US 5,118,986 A
• Filed: 06/21/1990
• Issued: 06/02/1992
• Est. Priority Date: 06/30/1989
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Takahashi, Toshihiko, Kawamura, Fumio, Hashimoto, Mitsuru, Ohta, Masafumi, Sakon, Yohta, Ohnuma, Teruyuki
• Primary Examiner(s): Yusko, Donald J.
• Assistant Examiner(s): Patel, Nimeshkumar D.
• Application Number:
  US07/541,533
• Time in Patent Office: 712 Days
• Field of Search: 313/504, 313/498, 313/509, 313/499, 428/917, 252/301.6 S, 252/301.4 H, 252/301.4 R, 430/82
• US Class Current: 313/504
• CPC Class Codes: G03G 5/02 Charge-receiving layers G03G5/153 takes precedence
• CPC Class Codes: H05B 33/14 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

Abstract

An electroluminescent device having:

an anode and a cathode; and

at least two organic compound layers sandwiched between said two electrodes,

at least one of said organic compound layers being a hole transporting layer containing a compound represented by the following general formula (I) ##STR1## wherein R¹ represents hydrogen atom, a lower alkyl group, a lower alkoxy groups, a halogen or a nitro group, A represents ##STR2## (wherein R² represents a lower alkyl group, a substituted or non-substituted aryl group or an aralkyl group, and R³ represents a lower alkyl group.)

Claims

1. An electroluminescent device comprising:

an anode and a cathode; and

at least two organic compound layers sandwiched between said anode and said cathode,

at least one of said organic compound layers being a hole transporting layer consisting essentially of a compound having the following formula ##STR16## wherein R¹ is hydrogen, C_1-5 alkyl, C_1-4 alkoxy, halogen or nitro, and A is ##STR17## wherein R³ is C_1-10 alkyl.

2. The electroluminescent device of claim 1, wherein said hole transporting layer consists essentially of a compound having formula I in which R¹ is hydrogen, C_1-2 alkyl, C_1-2 alkoxy, chlorine or bromine and R³ is C_2-7 alkyl.

3. The electroluminescent device of claim 1, wherein said hole transporting layer consists essentially of a compound selected from the group consisting of

1,1-bis((dibenzylamino)phenyl)propane,

5. The electroluminescent device of claim 1, wherein said device can be driven by applying a voltage of not more than 30 V.

7. The electroluminescent device or claim 1, wherein said device can maintain a luminescence of not less than 10 cd/m².

4. 1-bis((dibenzylamino)phenyl)butane,

1,1-bis((dibenzylamino)phenyl)-2-ethylhexane,

1,1-bis((di-4'"'"'-methylbenzyl)amino)propane, and

1,1-bis((di-4-'"'"'-bromobenzyl)amino)butane.

6. The electroluminescent device of claim 4, wherein said device can be driven by applying a voltage of 5-20 V.

8. The electroluminescent device of claim 6, wherein said device can maintain a luminescence of not less than 100 cd/m².

10. The electroluminescent device of claim 8, wherein said hole transporting layer consists essentially of a compound having formula I in which R¹ is hydrogen, C_1-2 alkyl, C_1-2 alkoxy, chlorine or bromine and R³ is C_2-7 alkyl.

11. The electroluminescent device of claim 8, wherein said hole transporting layer consists essentially of a compound selected from the group consisting of

1,1-bis((dibenzylamino)phenyl)propane,

1,1-bis((dibenzylamino)phenyl)butane,

1,1-bis((di-4'"'"'-methylbenzyl)amino propane, and

1,1-bis((di-4'"'"'-bromobenzyl)amino)butane.

12. The electroluminescent device of claim 8, wherein said device can be driven by applying a voltage of not more than 30 V.

13. The electroluminescent device of claim 11, wherein said device can be driven by applying a voltage of 5-20 V.

15. The electroluminescent device of claim 13, wherein said device can maintain a luminescence of not less than 100 cd/m².

9. An electroluminescent device comprising:

an anode and a cathode;

a luminescent layer; and

at least two organic compound layers sandwiched between said anode and said cathode,

at least one of said organic compound layers being a hole transporting layer consisting essentially of a compound having the following formula ##STR18## wherein R¹ is hydrogen, C_1-5 alkyl, C_1-4 alkoxy, halogen or nitro, and A is ##STR19## wherein R³ is C_1-10 alkyl.

14. The electroluminescent device of claim 30, wherein said device can maintain a luminescence of not less than 10 cd/m².

16. A method of reducing the driving voltage and improving the durability of an electroluminescent device containing an anode, a cathode, a luminescent layer and a hole transport layer, comprising:

sandwiching a hole transport layer consisting essentially of a compound having the following formula ##STR20## wherein R¹ is hydrogen, C_1-5 alkyl, C_1-4 alkoxy, halogen or nitro, and A is ##STR21## wherein R³ is C_1-10 alkyl, between said anode and said cathode.