Browse Prior Art Database

Host materials for triplet emitters

IP.com Disclosure Number: IPCOM000021063D
Publication Date: 2003-Dec-19
Document File: 55 page(s) / 3M

Publishing Venue

The IP.com Prior Art Database

Abstract

ID611302=PHNL030114

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Page 1 of 55

Carbazole compounds and use of

such compounds

in organic electroluminescent devices

Field

of

the invention

The invention relates

to carbazole compounds and the use of

         such compounds in organic electroluminescent devices.

5 Background

of the invention

An electroluminescent (EL) device

is

a device which emits light when

a

on

its electrodes.

If

the electroluminescent device comprises one or more organic compounds which

facilitate charge transport

and/or light emission

it is generally referred to as an

    organic electroluminescent device. Organic electroluminescent 10 devices

are low-voltage devices which

can be

made to emit any color and are

thin, light weight, flexible and/or of large area rendering such devices suitable

for display and lighting applications. An organic electroluminescent device

may comprise organic compounds

suitable voltage

is impressed

of relatively

low molecular weight, also

referred hereinafter

as small molecule electroluminescent devices,

or compounds

of high molecular weight, hereinafter

referred

    to 15 as

polymer electroluminescent devices.

Organic compounds

for use in

         organic electroluminescent devices, both small molecule and polymer, are generally conjugated

to facilitate charge transport

and/or light emission

in

the visible range

of

the electromagnetic spectrum. Although many

different conjugated compounds

for

use

in organic electroluminescent devices have hitherto been 20 suggested

in the art

there is still a need for further conjugated compounds which allow electroluminescent devices

to

be obtained having desirable properties.

Summary of the

invention

Accordingly,

it

is

an object

of

the invention, inter

alia,

to provide further

25 conjugated

compounds which

can be

suitably used

in organic electroluminescent devices.

In accordance with

the invention, this

object

is achieved

by

        a carbazole compound comprising a carbazole multimer unit of formula (I)

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Page 2 of 55

wherein each carbazole unit may be

unsubstituted or substituted with one or

more substituents and n is

larger than or equal to 2.

Preferably, 2 < n 100,000, more particular, 10,000. More preferably,

5 2<n<10 ,

orn

= 2, 3, 4 or 5.

The compounds in accordance with the invention can be

suitably used, if

appropriate in combination with other compounds, to provide red, green or blue light emission. More

in particular, when used

as such,

the compounds accordance with invention

may

be used

   to provide electroluminescent devices emitting blue light. 10 Further,

the compounds in accordance with invention may be

used to

provide

an electroluminescent device with

a hole-accepting level having energy comparable

to

the work-function

of high-work function materials such

as indium

tin oxide.

In

particular, the energy of the

hole-accepting level, expressed in terms highest occupied molecular orbital of the

    compound in accordance with the invention maybe 15 about

5.4

eV

or lower.

Still further,

the compounds in...