The present invention relates to a GaN-based heterostructure photodiode comprising
a P type layer, an N type layer, and an activity layer between the P type layer
and the N type layer. The P type layer, the N type layer and the activity layer
are made of GaN-based composition, and the activity layer is doped with borons
so as to modulate the band gap between the P type layer and the N type layer. Therefore,
the breakdown voltage can be increased and the light receiving ability can be promoted
so that the photodiode to be a light receiving element can has a better performance
for light detection.