Abstract: A photosensor provided herein includes a sensing structure and a microlens. The sensing structure includes an epitaxial layer, a deep trench and a scattering structure. The epitaxial layer has an illuminated surface and a non-illuminated surface. The deep trench isolation is located along an edge of the epitaxial layer. The scattering structure is embedded in the epitaxial layer and extends inwardly from the illuminated surface. The scattering structure includes a first circular ring pattern and a peripheral pattern. The deep trench isolation surrounds the scattering structure, the peripheral pattern is connected with the deep trench isolation and the first circular ring pattern is separated from the peripheral pattern and the deep trench isolation. The microlens is disposed on the epitaxial layer, wherein the illuminated surface of the epitaxial layer is relatively close to the microlens than the non-illuminated surface.