Light-emitting unit

A light-emitting unit, comprising:

• a substrate;
• a light-emitting element disposed on the substrate;
• a micro lens surrounding the light-emitting element, wherein the micro lens comprises a plurality of compound eye structures adjacent to each other,
• wherein in a top view, each of the plurality of compound eye structures has a length and a width, the light-emitting element has a length and a width, and the length and the width of the light-emitting element in the top view and the length and the width of each of the plurality of compound eye structures in the top view substantially satisfy:
• 1=(L1/W1)/(L2/W2)≤1.5, wherein W1 is the width of the light-emitting element in the top view, L1 is the length of the light-emitting element in the top view, W2 is the width of each of the plurality of compound eye structures in the top view, L2 is the length of each of the plurality of compound eye structures in the top view;
• and
• a reflective layer disposed between the substrate and the light-emitting element as well as between the substrate and the micro lens, wherein the micro lens has at least one surface in direct contact with the reflective layer.