A display device comprising a first sub-pixel (P1) and a second sub-pixel (P2) of substantially the same color; characterized in that the first sub-pixel (P1) comprises a first light emitting unit (PB11-1) and a first wavelength conversion layer (P12) disposed thereon, the first sub-pixel (P1) being configured to provide first light (B1 containing first excitation light emitted from the first light emitting unit (PB11-1) and first wavelength converted light converted by the first wavelength conversion layer (P12), the wavelength spectrum of said first light (B1) comprising a first main-peak (MP1) corresponding to the first wavelength converted light and a first sub-peak (SP1) corresponding to the first excitation light; and in that the second sub-pixel (P2) comprises a second light emitting unit (PB11-2) and a second wavelength conversion layer (P22) disposed thereon, the second sub-pixel (P2) being configured to provide second light (B2) containing second excitation light emitted from the second light emitting unit (PB11-2) and second wavelength converted light converted by the second wavelength conversion layer (P22), the wavelength spectrum of the second light (B2) comprising a second main-peak (MP2) corresponding to the second wavelength converted light and a second sub-peak (SP2) corresponding to the second excitation light; and in that a first wavelength difference (W1) between the first main-peak (MP1) and the second main-peak (MP2) is less than 20 nm, and in that the ratio of the first wavelength difference (W1) to a second wavelength difference (W2) between the first sub-peak (SP1) and the second sub-peak (SP2) is in the range of 0.2 to 0.8. a first sub-pixel (P1) and a second sub-pixel (P2) of substantially the same color; characterized in that the first sub-pixel (P1) comprises a first light emitting unit (PB11-1) and a first wavelength conversion layer (P12) disposed thereon, the first sub-pixel (P1) being configured to provide first light (B1 containing first excitation light emitted from the first light emitting unit (PB11-1) and first wavelength converted light converted by the first wavelength conversion layer (P12), the wavelength spectrum of said first light (B1) comprising a first main-peak (MP1) corresponding to the first wavelength converted light and a first sub-peak (SP1) corresponding to the first excitation light; and in that the second sub-pixel (P2) comprises a second light emitting unit (PB11-2) and a second wavelength conversion layer (P22) disposed thereon, the second sub-pixel (P2) being configured to provide second light (B2) containing second excitation light emitted from the second light emitting unit (PB11-2) and second wavelength converted light converted by the second wavelength conversion layer (P22), the wavelength spectrum of the second light (B2) comprising a second main-peak (MP2) corresponding to the second wavelength converted light and a second sub-peak (SP2) corresponding to the second excitation light; and in that a first wavelength difference (W1) between the first main-peak (MP1) and the second main-peak (MP2) is less than 20 nm, and in that the ratio of the first wavelength difference (W1) to a second wavelength difference (W2) between the first sub-peak (SP1) and the second sub-peak (SP2) is in the range of 0.2 to 0.8. <EOS>