ELECTROLUMINESCENT DEVICE COMPRISING A TRANSITION METAL OXIDE DOPED WITH A TRIVALENT RARE EARTH ELEMENT

• US 3,728,594 A
• Filed: 11/17/1971
• Issued: 04/17/1973
• Est. Priority Date: 11/17/1971
• Status: Expired due to Term

• Current Assignee: Perry Niel Yocom, Woongsoon Michael Yim
• Original Assignee: Perry Niel Yocom, Woongsoon Michael Yim
• Inventors: Yocom, Perry Niel, Yim, Woongsoon Michael
• Primary Examiner(s): Edlow, Martin H.
• Application Number:
  US05/199,708
• Time in Patent Office: 517 Days
• Field of Search: 317/235N,235AQ 313/18D,18A 331/94.5 65/30 252/31.4R
• US Class Current: 257/43
• CPC Class Codes: H01L 33/26 Materials of the light emitting region

Abstract

An electroluminescent device includes a layer including a transition metal oxide doped with a trivalent rare earth metal. The transition metal oxide has the general formula, Mxi(MiiOy)z where Mi is a Group IIA element or a group IIIB element, Mii is a transition metal, O is oxygen and the subscripts x, y and z denote the number of each of the elements depending on the valences of the particular elements used. The layer may be in the form of a single crystalline body of the doped transition metal oxide or particles of the transition metal oxide in a dielectric medium. A pair of spaced contacts are provided on the layer. For the single crystalline body one of the contacts is a blocking contact and the other is an ohmic contact. For the layer which includes the particles in a dielectric medium, both contacts are blocking contacts. Light is emitted from the layer when a current is applied through the layer between the contacts; DC current being used for the single crystalline body and AC current for the particles in a dielectric medium.

Claims

1. An electroluminescent device comprising:

a. a single crystalline layer of a transition metal oxide having the formula;

Mix(MiiOy)z wherein Mi is an element selected from the group consisting of Group IIA elements and Group IIIB elements;

Mii is a transition metal;

O is oxygen;

x denotes the number of Mi atoms, z denotes the number of Mii atoms, y times z denotes the number of O atoms, with x, y, and z being chosen depending on the valences of the particular elements used, said layer having an N type conductivity with a donor concentration of from 1014 to 1017 per cm3;

B. a dopant of a trivalent rare earth metal; and

c. a pair of spaced contacts on said layer.

2. An electroluminescent device in accordance with claim 1 in which one of said contacts is a blocking contact.

3. An electroluminescent device in accordance with claim 1 in which Mi is a metal selected from the group consisting of calcium, strontium, magnesium, barium, yttrium and lanthanum.

4. An electroluminescent device in accordance with claim 3 in which Mii is a transition metal selected from the group consisting of titanium, vanadium, niobium, tungsten, zirconium, molybdenum, hafnium and tantalum.

5. An electroluminescent device in accordance with claim 4 in which the rare earth metal is selected from the group consisting of praseodymium, neodymium, samarium, europium, terbium, dysprosium, holmium, erbium and thulium.

6. An electroluminescent device in accordance with claim 5 in which the amount of the rare earth metal in the body is between 0.01 and 0.5 percent by weight.