Colloidal PbS QDs heterostructure photodetector based on high-quality graphene

We propose a novel infrared photodetector composed of lead sulfide quantum dots and graphene which delivers a high responsivity of 3×10⁴ A/W at 980nm. We demonstrate the fast response to infrared light in different optical power. Simultaneously we have obtained the carrier mobility of 3500 cm² V⁻¹ s⁻¹ in graphene and Raman spectrum to verify its high quality.