Method of growing a ZnS:Mn phosphor layer for use in thin-film electroluminescent components

• US 6,113,977 A
• Filed: 09/11/1997
• Issued: 09/05/2000
• Est. Priority Date: 09/11/1996
• Status: Expired due to Term

• Current Assignee: Beneq Oy (Qingdao Sifang SRI & Intellectual Co., Ltd.)
• Original Assignee: Planar International Oy Ltd.
• Inventors: Harkonen, Gitte, Viljanen, Juha, Soininen, Erkki Lauri, Tornqvist, Runar, Lahonen, Marja
• Primary Examiner(s): CLEVELAND, MICHAEL B
• Application Number:
  US08/927,523
• Time in Patent Office: 1,090 Days
• Field of Search: 117/88, 117/104, 427/64, 427/255.32, 427/66, 427/255.33
• US Class Current: 427/64
• CPC Class Codes: C09K 11/574 with zinc or cadmium
• CPC Class Codes: H05B 33/10 Apparatus or processes specially adapted to the manufacture of electroluminescent light sources
• CPC Class Codes: H05B 33/12 Light sources with substantially two-dimensional radiating surfaces
• 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

The invention relates to a method of growing a ZnS:Mn phosphor layer suitable for use in thin-film electroluminescent components. According to the method, the ZnS:Mn phosphor layer is grown on a substrate by means of the ALE method using volatile zinc, sulfur and manganese compounds as the precursors. According to the invention, an organozinc compound such as diethylzinc or dimethylzinc is used as precursor for zinc, hydrogen sulfide or an organosulfur compound is used as precursor for sulfur, and an organomanganese compound or organic manganese complex compound is used as precursor for manganese. The invention provides a display component with drive-voltage-symmetrical light emission and stable characteristics of luminance level and turn-on voltage.

Claims

1. A method of growing a ZnS:

Mn phosphor layer for use in thin-film electroluminescent components, comprising growing the ZnS;

Mn phosphor layer on a substrate by an atomic layer epitaxy method using

an organozinc compound as a precursor for zinc selected from the group consisting of simple alkyl compounds, C₁ -C₆ dialkyl compounds, diaryl compounds, di-3-mercaptopropyl zinc, di-4-metoxybutyl zinc and dialkyl zinc compounds forming complex compounds with ethers or amines,

hydrogen sulfide or an organosulfur compound as a precursor for sulfur, and

an organomanganese compound or organic manganese complex compound as a precursor for manganese.

2. The method according to claim 1, wherein a simple alkyl compound is used as precursor for zinc.

3. The method according to claim 2, wherein the alkyl compound is selected from the group of diethylzinc and dimethylzinc.

4. The method according to claim 2, wherein the precursor for manganese is selected from the group of Mn(thd)₃, TCM, Mn(cpd)₃ and BCPM.

5. The method according to claim 1, wherein a thin-film electroluminescent component is prepared, comprising the steps of:

providing a substrate,

optionally forming an ion-diffusion layer on said substrate,

forming and patterning a set of first electrodes on said ion-diffusion barrier layer or on said substrate,

forming a first insulation layer on said electrodes,

growing said ZnS;

Mn phosphor layer on said first insulation layer,

forming a second insulation layer on said phosphor layer, and

forming and patterning a set of second electrodes on said second insulation layer.

6. The method according to claim 5, wherein the substrate being made from a material selected from the group of glass, Al₂ O₃ and silicon.

7. The method according to claim 5, wherein said first electrodes are made from a material selected from the group of indium-tin oxide, doped zinc oxide, Al, W and Mo.

8. The method according to claim 5, wherein said first insulation layer is formed by an aluminum oxide-titanium oxide multilayer structure.

9. The method according to claim 5, wherein said second insulation layer is formed by an aluminum oxide-titanium oxide multilayer structure.

10. The method according to claim 5, wherein said second electrodes are made from a material selected from the group of indium-tin oxide, doped zinc oxide and Al.

11. The method according to claim 5, wherein a second phosphor layer is grown between said ZnS:

Mn phosphor layer and said insulation layer deposited under or above said phosphor layer.

12. The method according to claim 11, wherein said second phosphor layer is selected from the group of SrS:

Ce and ZnS;

Mn layers.

13. The method according to claim 5, wherein a second insulation layer is grown between said ZnS:

Mn phosphor layer and said second phosphor layer deposited under or above said first phosphor layer.

14. The method according to claim 12, wherein said second phosphor layer is selected from the group of SrS:

Ce and ZnS;

Mn layers.

15. A method of forming a thin-film electroluminescent display, the method comprising the step of:

growing by an atomic layer epitaxy method a manganese-doped zinc sulfide (ZnS;

Mn) phosphor layer using

an organozinc compound as a zinc precursor selected from the group consisting of simple alkyl compounds, C₁ -C₆ dialkyl compounds diaryl compounds, di-3-mercaptopropyl zinc, di-4-metoxybutyl zinc, and dialkyl zinc compounds forming complex compounds with ethers or amines,

a sulfur-containing compound as a sulfur precursor, and

an organomanganese compound or an organic manganese complex as a manganese precursor.

16. The method of claim 15, wherein the simple alkyl compound is diethylzinc and dimethylzinc.

17. The method of claim 15, wherein the sulfur-containing compound is selected from the group consisting of hydrogen sulfide, carbon disulfide, dialkyl sulfur compounds, mercaptans, sulfur compounds with a ring structure, and sulfanes.

18. The method of claim 15, further comprising the steps of:

forming an ion-diffusion barrier layer on a substrate;

forming and/or patterning a layer comprising a conducting material;

forming an insulation layer;

forming the ZnS;

Mn layer; and

and forming a second insulation layer.

19. The method of claim 18, further comprising the step of:

forming and/or patterning a layer comprising a conducting material on the second insulation layer.

20. The method of claim 19, further comprising the step of:

forming a further ZnS;

Mn layer between the ZnS;

Mn layer and the insulation layer or the second insulation layer; and

forming a further insulation layer between the ZnS;

Mn layers.