A display panel comprising: an image generating device (IMGD) configured to emit light based on an input image signal; and a photoluminescence device configured to receive the emitted light from the image generating device (IMGD), the photoluminescence device comprising: colour conversion portions (CCP, CCP1, CCP2, CCP3) having a first refractive index and configured to convert the light emitted from the image generating device (IMGD) from one wavelength to another; a colour filter (CF1, CF2, CF3) configured to selectively pass light of a given range of wavelengths transmitted through the colour conversion portions (CCP, CCP1, CCP2, CCP3); a first low index of refraction layer (LIRL1) having a second refractive index and being disposed between the colour conversion portions (CCP, CCP1, CCP2, CCP3) and the colour filter (CF1, CF2, CF3), the second refractive index being lower than the first refractive index; and a second low index of refraction layer (LIRL2) having a third refractive index lower than the first refractive index, wherein each colour conversion portion (CCP, CCP1, CCP2, CCP3) is disposed between the first low index of refraction layer (LIRL1) and the second low index of refraction layer (LIRL2) and has a first surface facing the first low index of refraction layer (LIRL1), a second surface facing the second low index of refraction layer (LIRL2), and third surfaces connecting the first surface and the second surface to each other, and wherein the second low index of refraction layer (LIRL2) directly contacts all the surfaces of each colour conversion portion (CCP, CCP1, CCP2, CCP3) except the first surface. an image generating device (IMGD) configured to emit light based on an input image signal; and a photoluminescence device configured to receive the emitted light from the image generating device (IMGD), the photoluminescence device comprising: colour conversion portions (CCP, CCP1, CCP2, CCP3) having a first refractive index and configured to convert the light emitted from the image generating device (IMGD) from one wavelength to another; a colour filter (CF1, CF2, CF3) configured to selectively pass light of a given range of wavelengths transmitted through the colour conversion portions (CCP, CCP1, CCP2, CCP3); a first low index of refraction layer (LIRL1) having a second refractive index and being disposed between the colour conversion portions (CCP, CCP1, CCP2, CCP3) and the colour filter (CF1, CF2, CF3), the second refractive index being lower than the first refractive index; and a second low index of refraction layer (LIRL2) having a third refractive index lower than the first refractive index, colour conversion portions (CCP, CCP1, CCP2, CCP3) having a first refractive index and configured to convert the light emitted from the image generating device (IMGD) from one wavelength to another; a colour filter (CF1, CF2, CF3) configured to selectively pass light of a given range of wavelengths transmitted through the colour conversion portions (CCP, CCP1, CCP2, CCP3); a first low index of refraction layer (LIRL1) having a second refractive index and being disposed between the colour conversion portions (CCP, CCP1, CCP2, CCP3) and the colour filter (CF1, CF2, CF3), the second refractive index being lower than the first refractive index; and a second low index of refraction layer (LIRL2) having a third refractive index lower than the first refractive index, wherein each colour conversion portion (CCP, CCP1, CCP2, CCP3) is disposed between the first low index of refraction layer (LIRL1) and the second low index of refraction layer (LIRL2) and has a first surface facing the first low index of refraction layer (LIRL1), a second surface facing the second low index of refraction layer (LIRL2), and third surfaces connecting the first surface and the second surface to each other, and wherein the second low index of refraction layer (LIRL2) directly contacts all the surfaces of each colour conversion portion (CCP, CCP1, CCP2, CCP3) except the first surface.