| 摘要 |
<P>PROBLEM TO BE SOLVED: To lower a driving voltage of a display device having three-color organic EL elements emitting red light, green light, and blue light while improving light emission efficiency. <P>SOLUTION: Each organic EL element has an optical interference structure. A blue light emission layer 7B includes a host material and a light emitting material, a value of LUMO of a hole transport layer 6 is smaller than a value of LUMO of the host material of the blue light emission layer 7B, and the value obtained by subtracting a value of HOMO of the hole transport layer 6 from a value of HOMO of the host material of the blue light emission layer 3B is 0.5 eV or less. A film thickness adjusting layer 8 is arranged between a light emission layer of at least one of a red light emission layer 3R and a green light emission layer 3G, and the hole transport layer 6, hole mobility of the film thickness adjusting layer 8 is larger than carrier mobility of a light emission layer of an organic EL element where the film thickness adjusting layer 8 is arranged, and a value of HOMO of the film thickness adjusting layer 8 is equal to or less than a value of HOMO of the hole transport layer 6, and equal to or larger than a value of HOMO of the light emission material included in the light emission layer of the organic EL element where the film thickness adjusting layer 8 is arranged. <P>COPYRIGHT: (C)2013,JPO&INPIT |
