Micro-nano Processing Technology Of Graphene Nanowalls And Its Researches In Infrared Detector

Infrared detection technology expands human visualization from visible light to infrared regime.For the preparation of high-performance infrared detectors,the choice of materials is very important.Nowadays,the graphene nanowalls(GNWs)films with excellent optical and electrical properties have provided a new direction for the development of infrared detectors.However,related research on GNWs film infrared detectors is still in the initial stage.For this reason,the micro-nano processing technology of GNWs film was studied and optimized,and infrared detectors were prepared on this basis.The specific research results are illustrated as follows:1.Growth and characterization of the GNWs films.The GNWs films were obtained on different substrates by radio frequency plasma enhanced chemical vapor deposition technology,and their growth principles were studied.At the same time,the morphology and structure of GNWs films were analyzed by using approaches of SEM,Raman spectroscopy and AFM.2.Optimization of micro-nano processing technology of GNWs film.Firstly,the GNWs films was patterned using the double-layer photoresist process and reactive ion etching technology,and the GNWs films strip channels with clear boundaries and complete shapes were obtained.In addition,in order to solve the micro-bridge process problem of GNWs films and PDMS,easy-release silicon dioxide and silicon nitride with good insulation properties were selected as supporting materials for the underlying substrate.And property of the PDMS was changed from hydrophobic to hydrophilic using oxygen plasma etching technology,which improve the process compatibility problem between GNWs films and PDMS.The influence of the wet etching process on the suspended structure was analyzed,and proposed the use of hydrofluoric acid to etch silicon dioxide for microcavity release.3.Preparation and research of infrared detector based on GNWs films.Firstly,based on the successful realization of the GNWs patterning process,photoconductive infrared detectors with different substrates(n-type silicon,intrinsic silicon,p-type silicon)and GNWs films were prepared,band structure of GNWs films/silicon heterojunction,photoelectric performance was tested,the photocurrents of the three devices were compared in the near infrared band and the visible band.It is found that the GNWs film/n-type silicon device has the largest photocurrent response,and the GNWs film/p-type silicon device has the smallest photocurrent response.Calculate the Schottky barrier heights of the three devices based on the theory of hot electron emission,the Schottky barrier heights of the GNWs films/silicon(n-type silicon,intrinsic silicon,p-type silicon)heterojunctions are 0.73 eV,0.69 eV,and 0.63 eV,respectively.It is concluded that the higher the barrier,the more photogenerated carriers injected into the GNWs film,and the greater the photoresponse current.In addition,a high TCR infrared thermal detector was designed based on the GNWs films and PDMS micro-bridge technology.Its preparation process was experimentally explored.