Abstract
The present invention provides a photosensing device and a phosensing module. The photosensing device includes a photovoltage sensing mechanism, a graphene layer and a semiconductor layer. The graphene layer is sandwiched between the semiconductor layer and a substrate. The photovoltage sensing mechanism senses the photovoltage created by light impinging on the graphene-semiconductor heterojunction. The strength of the photovoltage is used to indicate the level of illumination of the impinging light.