Simulation Of Photo Detector Based On Perovskite Materials

With a series of excellent characteristics such as strong light absorption capacity,low defect density,high carrier lifetime and mobility product,and high resistivity at room temperature,perovskite materials have become one of the ideal materials for preparing high-sensitivity and fast-response photodetectors.First,it can achieve light response from deep ultraviolet to near-infrared wavelength range,including broadband,narrow-band light detection and high-energy particle sensing,etc.A large number of experiments have proved that perovskite materials have good development prospects in the field of photoelectric detection.At present,photodetectors based on perovskite materials have become a research hotspot.Material properties and device structure are the key factors affecting the performance of photodetectors.On the one hand,experts and scholars improve carrier transport by improving the material grain boundaries and defect density.Capability,on the other hand,by improving the device structure to obtain excellent performance parameters such as high detection rate and high response speed.On the basis of experiments,using software to simulate and optimize the design of photodetectors of different materials and structures can provide a better theoretical basis for the research of photodetectors.Therefore,this paper studies the characteristics of photodetectors with different structures from the perspective of simulation,and analyzes the influencing factors of detector performance.The specific work done is as follows:(1)The structure and internal working mechanism of PN junction,PIN type and field effect tube photodetector have been analyzed.COMSOL software was used to establish simulation models of photodetectors with three structures,and the photoelectric characteristics of different structures were compared.Compared to PN junction photodiode,by introducing an electron/hole transport layer and a low-doped intrinsic layer,the photocurrent of the PIN photodetector with Cu₂O/CH₃NH₃Pb I₃/PCBM(fullerene derivative compound)structure has been increased by 3.3 times,and the switching ratio has been increased by 2.1times.The turn-on voltage V_T of the field effect tube photodetector is 0.2V.At a gate voltage of 2V,the photocurrent is about 0.15?A,and the current on-off ratio is about 7.9×10⁵.(2)The effects of intrinsic layer material,electron/hole transport layer and intrinsic layer thickness in PIN type perovskite photodetector on the performance of the device are studied.The photodetectors based on different intrinsic layer materials including CH₃NH₃Pb I₃ and Cs Pb Br₃ obtain maximum response at wavelengths of 800nm and 540 nm,respectively.In addition,the photocurrent of the detector with Cu₂O as the hole transport layer was increased from 0.12?A to 2.39?A.PCBM as an electron transport layer weakens the I-V characteristics of the photodetector to a certain extent due to its low electron mobility and defect density.The relationship between response time,quantum efficiency and intrinsic layer thickness is obtained through numerical software simulation.The simulation results provide a reference for the selection of intrinsic layer material and thickness and electron/hole transport layer in the PIN perovskite photodetector.