For calculations, the full area of graphene (5 × 50 µm) was taken into account, as noise originates over the complete graphene area. After the nanoprinting, the pristine QDs ligands were exchanged with shorter 1,2-ethanedithiol ligands by a solid-state ligand exchange (see Experimental Section) resulting in a QDs layer thickness reduction from 410 nm to 340 nm as determined by atomic force microscopy (Figure , Supporting Information). The phototransistor was electro-optically characterized by a responsivity setup with modulated light (see Experimental Section). Figure shows a top-view optical bright-field image of the device, and Figure presents the spectral dependence of the phototransistor's responsivity operating at a temperature of 80 K. A first excitonic absorption feature is observed at a wavenumber of 4000 cm -1 in agreement with the HgTe QD thin film absorbance measured with a Fouriertransform infrared spectrometer at a temperature of 300 K (Figure , Supporting Information).