Preparation?doping And Photoelectric Properties Of Carbon-based Nanomaterials

Graphene has been receiving extensive attentions since its discovery because of the excellent properties.However,the application in photodetector field of graphene was limited by the property of zero-bandgap semi-metal.Therefore,developed two materials:graphene quantum dots?GQDs?and multilayer graphene,based on the graphene researches.In the study of GQDs,we found that doping some elements could effectively adjust the band structure and improve electrical properties,thus making GQDs can be better applied in the field of optoelectronics.In recent years,the preparation methods of multilayer graphene have been research focus,and the main methods are chemical vapor deposition?CVD?,plasma enhanced chemical vapor deposition?PECVD?and magnetron sputtering.In this paper,we start from preparing sulfur doped graphene quantum dots?S-GQDs?and multilayer graphene,and then studied their photoelectric properties respectively.1.The S-GQDs were prepared by the one step synthesized combustion?T-X-J?method,using the available and non-toxic liquid paraffin and carbon disulfide?CS₂?as raw materials.Raman spectroscopy?Raman?,transmission electron microscopy?TEM?,Fourier transform infrared?FTIR?spectra and Ultraviolet-Visible absorption?UV-Vis?spectra were adopted to characterize the morphologies,structures,components,absorptions and luminescence properties of S-GQDs.2.The photodetector based on S-GQDs has been produced.We tested the performances of the detector with 365 nm UV light irradiation under different power densities.The results show that with the luminous power density of 0.06 m W/cm²,the device obsess the highest responsitivity and detectivity,up to 307 A/W and 1.5×10¹⁴Jones respectively.The photoactive layer of the device was prepared by mixing S-GQDs with polyvinylcarbazole?PVK?,where PVK has the hole transport abilities.In order to investigation the influences of PVK,we prepared photodetector with sole PVK.In contrast tests under same circumstances,the responsitivity of S-GQDs device was1.5×10⁵%higher than PVK devices and the detectivity of S-GQDs device was 5.8×10⁴%higher than PVK device.3.Using graphite target as carbon source to prepare the multi-layer graphene films by magnetron sputtering with annealing.The microstructures,morphologies,compositions and properties of the films were characterized by Raman,FTIR and UV-Vis-IR.We exploratory prepared photodetector based on multilayered graphene and tested its performances.When the device was irradiated with 850 nm near-infrared light under different power densities at room temperature,with the luminous power density was 0.109 m W/cm²,obtained the highest responsitivity and detectivity were 2A/W and 2×10¹¹ Jones.