Diode array

A diode array, comprising:

• a substrate;
• a first LED group, comprising a plurality of light emitting diodes with a first wavelength and arranged in an array on the substrate;
• a second LED group, comprising a plurality of light emitting diodes with a second wavelength and arranged in an array on the first LED group;
• and
• a third LED group, comprising a plurality of light emitting diodes with a third wavelength and arranged in an array on the second LED group,
• wherein each of the light emitting diodes in each LED group comprises a first type semiconductor layer, a second type semiconductor layer, and a light emitting layer located between the first type semiconductor layer and the second type semiconductor layer,
• wherein at least one of the light emitting diodes in each LED group has:
• a current blocking region formed, with respect to a top down view, about an outer edge of the at least one light emitting diode and abutting a vertically extending boundary of the second semiconductor layer,
• wherein an outer perimeter of the current blocking region is equal to or less than 400 micrometers (μm), and
• wherein the first, the second, and the third LED groups are stacked in sequence along a normal direction of the substrate.