Optical fingerprint sensor and display module

An optical fingerprint sensor, comprising a photodiode and a switching thin film transistor connected to the photodiode, wherein the photodiode comprises a first electrode made of a light-absorbing conductive nano-material;

• wherein the first electrode is located in a same layer as a second electrode of the switching thin film transistor, and the first electrode comprises a light-entering end surface facing a light-entering side and a side surface connected to the light-entering end surface, the side surface comprises a curved portion, and the second electrode is at least connected to the curved portion;
• and
• wherein the second electrode is arranged to fully surround the first electrode and be connected to each position of the side surface.