Display device
A display device includes an anode, a hole injection layer, a hole transport layer, a blue light emitting layer, a hole blocking layer, an electron transport layer and/or an electron injection layer, and a cathode, which are stacked in this order, and has the following characteristics (i), (ii), and (iii): (i) the hole mobility of the blue light emitting layer≥the electron mobility of the blue light emitting layer, (ii) the hole mobility of the hole transport layer≥the electron mobility of the blue light emitting layer, and (iii) |the HOMO value of the blue light emitting layer−the HOMO value of the hole blocking layer|≥0.4 eV.
1. A display device, comprising an anode, a hole injection layer, a hole transport layer, a blue light emitting layer, a hole blocking layer, an electron transport layer and/or an electron injection layer, and a cathode, which are stacked in this order, and having the following characteristics (i), (ii), and (iii):
(i) the hole mobility of the blue light emitting layer≥the electron mobility of the blue light emitting layer,
(ii) the hole mobility of the hole transport layer≥the electron mobility of the blue light emitting layer, and
(iii) |the HOMO value of the blue light emitting layer−the HOMO value of the hole blocking layer|≥0.4 eV.
2. The display device according to claim 1 , wherein the film thickness of the blue light emitting layer is less than 15 nm.
3. The display device according to claim 1 , wherein the HOMO value of the hole blocking layer is less than −6.2 eV.
4. The display device according to claim 1 , wherein the electron mobility of the hole blocking layer is 10 −5 or more and 10 −4 or less (cm 2 /Vs).
5. The display device according to claim 1 , wherein the following relationship is satisfied:
the electron mobility of the hole blocking layer≥the electron mobility of the blue light emitting layer.