Research On Photodetector With The Structure Of Transistor Based On Inorganic Perovskites

Inorganic perovskites?inorganic perovskite quantum dots?IPQDs?and inorganic perovskite films?have many excellent characteristics,such as large absorption coefficient,high charge carrier mobility and large diffusion length and so on.They have been widely employed in light-emitting diodes,solar cells and photodetectors and other optoelectronic applications.The three main methods for the synthesis of IPQDs were explored.Through the comparative analysis of the properties of the synthesized QDs,thermal injection was eventually chosen to prepare the QDs CsPbBr₃,the QDs with the luminescence peak of 512nm and the half-peak width of 24nm were obtained.And different purification methods and times have also been explored to improve the performance of QDs in photoelectric devices.The photodetector with IPQDs as active layer was prepared by combining the excellent properties of IPQDs with the transistor structure.In order to improve the performance of the device,the zinx oxide quantum dots?ZnO QDs?prepared by sol-gel method were introduced.Because of the large absorption coefficient and long diffusion lengths of charge carriers in perovskites as well as the high electron mobility of ZnO,the photo-induced carriers can be separated efficiently,employing ZnO film as the electronic transport layer.As a consequence,this device has exhibited a high responsivity of 43.5 A/W,an on/off ratio of 5.6×10⁴ under365 nm light illumination with the intensity of 3 mW/cm²,which are enhanced for 62-fold and 560-fold compared with the without ZnO phototransistor.And the specific detectivity can be estimated to be 5.02×10¹¹ Jones.The preparation of inorganic perovskite films has also been studied,the traditional synthesis method was improved and the clear precursor was obtained.The uniform and compact perovskite films were obtained by controlling the ratio of caesium bromide?CsBr?and lead bromide?PbBr₂?.The film is applied to the preparation of photodetector as an active layer,and finally a device with a certain photoelectric response is obtained.