Tuning photo-response and electronic behavior of graphene quantum dots synthesized via ion irradiation

Abstract

The tuning of the photoresponse and electronic structure for ion induced graphene quantum dots (I-GQDs), through variations in the ion irradiation processing of monolayer graphene, is demonstrated. Synthesis of nano-dimensional quantum dots (3–9 nm) was observed for graphene after irradiation in the ion energy range of 100–250 eV. Remarkably, the photo-response from these GQDs can be manipulated and significantly enhanced simply with the change of ion energy. Changes to the photo-response are reflected in the appearance of an optical mode near 560 nm, and the enhancement of UV-regime absorbance by nearly 70%. The results display a method that can be useful in designing graphene quantum dot based photodetectors, in a single step process with ion irradiation, without incorporation of any metal-nanoparticles or hybrid-metal platforms. Changes in the UV absorbance are of immense significance having many potential applications in UV based detectors.