The invention relates to the technical field of
semiconductor devices, in particular to a multiband light-emitting
diode epitaxial structure and a preparation method thereof. The multiband light-emitting
diode epitaxial structure sequentially comprises a substrate, a buffer layer, an N-type
semiconductor layer, a low-
temperature stress release layer, a multi-
quantum well light-emitting layer, an
electron blocking layer and a P-type
semiconductor layer from bottom to top, the multi-
quantum well light-emitting layer comprises four sub-
layers, namely a first long-wave cyan light multi-
quantum well layer, a second short-wave cyan light multi-
quantum well layer, a third long-wave
blue light multi-
quantum well layer and a fourth short-wave
blue light multi-
quantum well layer which are sequentially stacked and grown from bottom to top, and the light-emitting wavelengths are sequentially decreased. Meanwhile, by combining the design of the sub-
layers of the
multiple quantum well light-emitting
layers and through the synergistic effect of exciting light of all wave bands, the overall excitation efficiency can be improved, full-spectrum
white light is output, the full-spectrum
white light is closer to
sunlight, the light-emitting efficiency is high, the color rendering property is good, the stability is better, and harm to human eyes is small.