Light-emitting device

Abstract

The conventional light-emitting element formed by an electroluminescent material has a problem due to poor color purity of light emission. Accordingly, it is an object of the present invention to provide a high luminance and high efficiency light-emitting device formed by an organic compound material. The invention provides a light-emitting device in which an organic compound layer that emits light having an emission peak with a half-band width of at most 10 nm upon applying current is interposed between a pair of electrodes is provided. The variation of emission peak intensity depending on a current density can be sorted by two linear regions with different gradients. A region of a sharp gradient is at a higher current density side compared to a region of a slow gradient. TFTs are provided to each pixel in order to perform active matrix driving.

1 . A light-emitting device comprising an organic compound layer capable of emitting non coherent light and coherent light.  
   
   
       2 . A light-emitting device comprising an organic compound layer capable of emitting luminescence and laser light.  
   
   
       3 . A light-emitting device comprising an organic compound layer interposed between a pair of electrodes, 
 wherein the organic compound layer emits light having an emission peak with a half-band width of at most 10 nm.    
   
   
       4 . A light-emitting device comprising an organic compound layer formed between a pair of substrates, 
 wherein the organic compound layer emits light with an emission spectrum having a plurality of peaks, and    the organic compound layer is formed to have a thickness of a half wavelength or integral multiple of the half wavelength in order to form a stationary wave with respect to light at a specified wavelength in the emission spectrum.    
   
   
       5 . A light-emitting device comprising: 
 light-emitting elements arranged in a matrix form, each comprising an organic compound layer capable of emitting coherent light and non coherent light; and    a transistor connected to one of the light-emitting elements for controlling light emission from said one of the light-emitting elements.    
   
   
       6 . A light-emitting device comprising: 
 light-emitting elements arranged in a matrix form, each comprising an organic compound layer capable of emitting luminescence and laser light; and    a transistor connected to one of the light-emitting elements for controlling light emission from said one of the light-emitting elements.    
   
   
       7 . A light-emitting device comprising: 
 light-emitting elements arranged in a matrix form, each comprising a pair of electrodes and an organic compound layer disposed therebetween; and    a transistor connected to one of the light-emitting elements for controlling light emission from said one of the light-emitting elements,    wherein the organic compound layer emits light having an emission peak with a half-band width of at most 10 nm.    
   
   
       8 . A light-emitting device comprising: 
 light-emitting elements arranged in a matrix form, each comprising an organic compound layer; and    a transistor connected to one of the light-emitting elements for controlling light emission from said one of the light-emitting elements,    wherein the light-emitting elements are formed between a pair of substrates,    the organic compound layer emits light with an emission spectrum having a plurality of peaks, and    the organic compound layer is formed to have a thickness of a half wavelength or integral multiple of the half wavelength in order to form a stationary wave with respect to light at a specified wavelength in the emission spectrum.    
   
   
       9 . The light-emitting device according to  claim 1 , wherein the light-emitting device is used for a display portion of an electronic apparatus selected from the group consisting of TV set, video camera, computer, sound reproduction device, digital camera, and cellular phone.  
   
   
       10 . The light-emitting device according to  claim 2 , wherein the light-emitting device is used for a display portion of an electronic apparatus selected from the group consisting of TV set, video camera, computer, sound reproduction device, digital camera, and cellular phone.  
   
   
       11 . The light-emitting device according to  claim 3 , wherein the light-emitting device is used for a display portion of an electronic apparatus selected from the group consisting of TV set, video camera, computer, sound reproduction device, digital camera, and cellular phone.  
   
   
       12 . The light-emitting device according to  claim 4 , wherein the light-emitting device is used for a display portion of an electronic apparatus selected from the group consisting of TV set, video camera, computer, sound reproduction device, digital camera, and cellular phone.  
   
   
       13 . The light-emitting device according to  claim 5 , wherein the light-emitting device is used for a display portion of an electronic apparatus selected from the group consisting of TV set, video camera, computer, sound reproduction device, digital camera, and cellular phone.  
   
   
       14 . The light-emitting device according to  claim 6 , wherein the light-emitting device is used for a display portion of an electronic apparatus selected from the group consisting of TV set, video camera, computer, sound reproduction device, digital camera, and cellular phone.  
   
   
       15 . The light-emitting device according to  claim 7 , wherein the light-emitting device is used for a display portion of an electronic apparatus selected from the group consisting of TV set, video camera, computer, sound reproduction device, digital camera, and cellular phone.  
   
   
       16 . The light-emitting device according to  claim 8 , wherein the light-emitting device is used for a display portion of an electronic apparatus selected from the group consisting of TV set, video camera, computer, sound reproduction device, digital camera, and cellular phone.