Research On Graphene/Silicon Photodiode Of Graphene Silicon Schottky Junction

Graphene is a new monolayer carbon materials made of carbon atoms packing into a two-dimensional honeycomb lattice structure. Because of its special structure, it has large carrier mobility, high speed of electron sport, large light transmission rate, excellent mechanical properties and thermal conductivity compared with most of the existing metallic and semiconducting materials. Since its discovery, it has been widely concerned by researchers. The graphene we used are purchased by ACS material company, and it’s characterized by using optical microscopy and Raman spectroscopy. Study graphene/silicon photodiodes processing technology and optimize it. The main results are as follows:(1) The manufacturing process and performance analysis of graphene/silicon photoelectric diode were studied. First, using Raman, AFM and SEM et al techniques to characterize the quality of graphene and the structure of Gr/Si. The Ⅰ-Ⅴ characteristics, responsivity, quantum efficiency and response time of the device were analyzed. The main parameters of the diode were attracted using semiconductor Schottky theory, including the work function of graphene and silicon, the ideal factor and serial resistance.(2) The manufacturing process and performance analysis of SiQDs/Gr/Si heterostructure were studied. First, the spin-coating process of SiQDs film and the manufacturing process of the device were studied. Then, the responsivity, quantum efficiency, response time and noise characteristic of the device were studied. Last, the mechanism of SiQDs in the process of increasing responsivity was analyzed. Three causes are attributed to SiQDs:1. The down-shift of SiQDs can increase the responsivity of the device in the UV wave length; 2. The optical anti-reflection of SiQDs films can increase the response in all wave length; 3. The charge transfer between SiQDs and graphene increases the barrier hight of graphene/silicon, thus enhancing the separation efficiency of photo-excited carriers and increasing the electron transportation.