Biometric sensor, display apparatus, and method of fabricating biometric sensor

A method of fabricating a biometric sensor, comprising:

• providing a first base substrate;
• providing a second base substrate facing the first base substrate;
• forming a plurality of photosensors on the first base substrate and configured to detect at least a portion of a light totally reflected by a surface of the second base substrate facing away the first base substrate, thereby detecting a biometric information;
• forming a low refractive index layer on a side of the plurality of photosensors distal to the first base substrate;
• and
• forming a high refractive index layer on a side of the low refractive index layer distal to the first base substrate and directly adjacent to the low refractive index layer, the high refractive index layer is made of a material having a refractive index higher than a refractive index of a material of the low refractive index layer;
• wherein the low refractive index layer and the high refractive index layer are formed to exclude a portion of a reflected light reflected by the surface of the second base substrate facing away the first base substrate having an angle of incidence with respect to an interface between the low refractive index layer and the high refractive index layer outside a threshold range from entering into the plurality of photosensors;
• forming the low refractive index layer comprises forming a plurality of concave lenses configured to diffuse at least a portion of the reflected light reflected by the surface of the second base substrate facing away the first base substrate and transmitted toward the plurality of photosensors;
• the high refractive index layer is made of a material having a refractive index higher than a refractive index of a material of the plurality of concave lens;
• the plurality of concave lenses and the high refractive index layer are formed to exclude the portion of the reflected light reflected by the surface of the second base substrate facing away the first base substrate having the angle of incidence with respect to an interface between the plurality of concave lenses and the high refractive index layer outside the threshold range from entering into the plurality of photosensors;
• and
• a respective one of the plurality of concave lenses is formed between a respective one of the plurality of photosensors and the high refractive index layer.