Research On The Graphene/Semiconductor Film Hybrid Photodetector

Graphene/semiconductor film hybrids based photodetectors have attracted abroad attention because of their ultrahigh performance.High-and reproducible-performance photodetectors are critical to the development of many technologies,which mainly include one-dimensional?1D?nanostructure based and film based photodetectors.The former suffer from a huge performance variation because the performance is quite sensitive to the synthesis microenvironment of 1D nanostructure.While the photodetector based on the thin film structure has a greater advantage in stable performance.In this paper,a complete preparation,performance test and functional adjustment of graphene /semiconductor thin film hybrid photodetector are carried out in order to prepare a better photodetector.The first chapter of this paper introduces the knowledge about semiconductor and semiconductor photodetector,elaborates the research background and research content,and the importance and innovation of this thesis are also clarified.In the second chapter,the preparation and working principle of graphene/semiconductor thin film hybrid photodetector are mainly described.The drugs and instruments used in the experiment process are introduced,and a detailed description on structural ananlysis instruments is presented.In the experimental part of the third chapter,the graphene/semiconductor thin film hybrid photodetector was prepared by combining the graphene with extremely high carrier mobility and the semiconductor thin film deposited by electron beam coating,and the photoresponse test was carried out.The results show that the graphene/semiconductor thin film mixed photodetector prepared in this experiment not only achieves the response rate of 1.7×107A/W and the corresponding speed of about 50 ms,but also shows the high degree of repeatability.The photodetector prepared by this method is compatible with the traditional process and has significant advantages in a wide range of applications.In the fourth chapter,a more in-depth study of the graphene/semiconductor thin film hybrid photodetector model was proposed.In this experiment,alloyed Zn_xCd_1-xS?0 ? x ? 1?films with complete compositional tunability have been successfully prepared by e-beam evaporation method via changing the mole ratio of ZnS to CdS in target.UV–visible optical absorption measurements show that the composition-dependent band-edge absorption is generated in as-prepared alloyed Zn_xCd_1-xS films,with the energy gaps continuously shifted from 2.41 eV?x = 0,CdS?to 3.67 eV?x = 1,ZnS?.After graphene is transferred onto alloyed Zn_xCd_1-xS films,band-tunable photodetectors are achieved based on graphene/alloyed Zn_xCd_1-xS films hybrids with cut-off wavelength in spectra response gradually changed from 410 nm to 580 nm.Obviously,the method introduced in this work can be extended to fabricate other graphene/alloyed ternary film hybrids based photodetectors with band tunability in visible and infrared region.In the last chapter,we give an overview on the deficiency in this dissertation,an some possible directions of future work are also pointed out.