Light-emitting element, and display device

A light-emitting element comprising:

• a first transparent electrode;
• a second transparent electrode;
• a light-emitting layer provided between the first transparent electrode and the second transparent electrode, the light-emitting layer including quantum dots;
• a first selectively reflective layer provided at an opposite side to the light-emitting layer with respect to the first transparent electrode, the first selectively reflective layer having a reflection band having a higher reflectivity than a reflectivity of another band;
• and
• a second selectively reflective layer provided at an opposite side to the light-emitting layer with respect to the second transparent electrode, the second selectively reflective layer having a reflection band having a higher reflectivity than a reflectivity of another band,
• wherein a wavelength at a long wavelength end in the reflection band of the first selectively reflective layer
• is longer than a wavelength at which a light emission spectrum due to electroluminescence of the quantum dots has a half value of a peak value of the light emission spectrum due to the electroluminescence of the quantum dots at a shorter wavelength side than a peak wavelength of the light emission spectrum due to the electroluminescence of the quantum dots, and
• is shorter than a wavelength at which the light emission spectrum due to the electroluminescence of the quantum dots has the half value of the peak value of the light emission spectrum due to the electroluminescence of the quantum dots at a longer wavelength side than the peak wavelength of the light emission spectrum due to the electroluminescence of the quantum dots, and
• a wavelength at a long wavelength end in the reflection band of the second selectively reflective layer
• is longer than the wavelength at which the light emission spectrum due to the electroluminescence of the quantum dots has the half value of the peak value of the light emission spectrum due to the electroluminescence of the quantum dots at the shorter wavelength side than the peak wavelength of the light emission spectrum due to the electroluminescence of the quantum dots, and
• is shorter than the wavelength at which the light emission spectrum due to the electroluminescence of the quantum dots has the half value of the peak value of the light emission spectrum due to the electroluminescence of the quantum dots at the longer wavelength side than the peak wavelength of the light emission spectrum due to the electroluminescence of the quantum dots.