High Sensitivity Photodetector Based on Graphene-Germanium Quantum Dot*

Graphene has shown great potential for realizing optoelectronic devices, especially for photodetectors. Here, we experimentally demonstrate a fabrication of photodetector based on graphene-germanium quantum dots that can detect a broadband spectrum from visible to infrared region. The device, based on graphene-germanium quantum dots, demonstrates an improved responsivity and response time. Characteristically, the fabricated photodetector shows a responsivity of 1,500 A/W at room temperature and a fast photoresponse time in the order microseconds. The results address key challenges for broadband photodetectors in the visible to infrared region, and also are promising for the development of graphene-based optoelectronic applications.