Research On Perovskite Detector Based On Charge Collection Narrowing Effect

Perovskite material is a new type of semiconductor material.Because of its advantages such as smaller exciton binding energy,higher absorption coefficient,and longer carrier diffusion length,it can be used in the preparation of photovoltaic devices and photodetector devices.This aspect has a good effect and is a direction that attracts a lot of attention from the academic community.Developed to now,with the synthesis of new perovskite materials,advances in manufacturing processes and optimization of device structures,the performance of perovskite devices has also made great progress.The work of this dissertation is to explore the influence of the perovskite photodetector on the detection performance by controlling the ratio of different halogen elements and controlling the thickness of the perovskite film.This research including the following two parts:A perovskite detector based on charge collection narrowing effect was first prepared.The device structure was ITO/PEDOT:PSS/MAPbI3-xBrx?0?x?3?:RhB/PCBM/C60/LiF/Ag.It is characterized by doping Rhodamine B into the perovskite to prepare a mixed solution,and spin-coating the perovskite active layer into a thick film,so that it has a charge collection narrowing effect,which enables the device to achieve narrow-band detection capabilities.The advantage of doping Rhodamine B is that the thickness of the active layer film can be controlled within 1?m,and the perovskite film above 1?m has high requirements for experimental equipment and processes,and the optimal film thickness is controlled by different thickness adjustments to 600nm.Secondly,by adjusting different ratios of I and Br,the detector can be adjusted to have different light band detection capabilities under different halogen ratios.The best performance was obtained when the I/Br ratio was 2:1.The FWHM of the detector was 80nm and the detection rate was 4.2*10¹¹Jones.Then,based on the perovskite detector with the above structure,when the light is irradiated from the side of the Ag electrode,the device has a broadband detection capability.Through software simulation and experimental data analysis,the effects of Ag electrodes of different thicknesses on the detection performance are designed,and by designing a narrow working area to limit incident light on the device,it is proved that the light is incident from the Ag electrode and not leaked elsewhere.A dual-function perovskite detector with wide/narrow-band detection capability is provided.When the Ag electrode is 20nm,the device has the best performance,the detection band is 450nm-800nm,and the detection rate is 1.9*10¹¹Jones.To sum up,compared with traditional devices,the perovskite photodetectors prepared in this study have both broadband and narrowband detection capabilities,which provides a new idea for the diversity of perovskite photodetectors.