| Infrared up-conversion devices have attracted tremendous interest because of their huge prospects in infrared imaging,and near-infrared detection materials are the key to achieve high performance Infrared up-conversion devices.In recent years,the development of organic Near-infrared photodetectors(NIR PDs)due to the limited selection of materials and their narrow infrared is limited.While due to its excellent electrical and optical properties,Ge has attracted more and more attention.The monocrystalline Ge and GeSn alloys grown by molecular beam epitaxy have good absor:ption characteristics in NIR band,and the NIR PDs based on the above two materials with excellent performance.Based on Ge’s good optical characteristics,this thesis aims to fabricate amorphous Ge films with good NIR absorption characteristics.First,the NIR absorption characteristics of Ge compound prepared by vacuum thermal evaporation have been studied.By varying the doping ratio of GeSn alloy,the absorption can be changed.The results show that with the increase of Sn concentration,the band gap of alloy material decreases.The films surface morphology roughness increases.In order to further improve the film absorption characteristics,a buffer layer is introduced into the film.The results show that adding a thin buffer layer can improve the surface of the film and its NIR absorption characteristics.Second,thin films of Ge nanomaterials made by spinning coating showed good absorption characteristics in NIR band.So,Ge powder is selected as the research object,analyzed the structural properties and prepared solution,by spinning coating fabricated the film.The results shows that the 1%hydrochloric acid can effectively remove the germanium dioxide from the surface of germanium powder,ultrasonic can improve the solution dispersion.The Ge films and Ge-NPB compound films have absorption in the NIR band,and the absorption is the amorphous germanium. |
