Effect Of Additive Treating Active Layer On The Performance Of Perovskite Photodetector

Photodetectors(PDs)is a kind of photoelectric devices convert optical signals into electrical signals,sensing and measuring light signals is significant for our daily life and social production.In recent years,perovskite has become a global research hotspot and is expected to become a new generation of photoelectric materials due to its excellent photoelectric properties,such as easy control of forbidden band width,flexibility,low material cost and compatible solution method,etc.However,due to poor air stability of perovskite materials,the perovskite thin film prepared by solution method has many interface defects,which seriously hinder the performance of Perovskite photodetector(PPDs).Therefore,one of the key factors to prepare high-performance PPDs is to passivate perovskite film defects and improve the crystallinity and film quality of perovskite by appropriate methods.The specific research contents of this paper are as follows:(1)The influence of preparation technology on the crystallization of perovskite thin films and performance of device was studied.Specifically,the influences on the morphology of perovskite films were studied by adjusting the time of dropping antisolvent,rotation speed during spinning,annealing time and temperature.The final experiment shows that the perovskite film is the most uniform and smooth at the spinning speed of 4000 rpm,antisolvent is dropped at the 10th s,and annealed at 100°C for 20 min.At the same time,the specific detection rate(D*)of PPDs developed at300nm-700nm reaches 10¹² Jones,which are in line with conventional PPDs devices.(2)The influence of additive P3HT:IHIC on the preparation of perovskite thin films was studied.The results show that C=O,S=O and C?N bond in P3HT:IHIC is able to produce Lewis acid-base binding effect with the free Pb²⁺in perovskite film.Thus,the defects of perovskite film are passivated and the crystallinity of perovskite film and quality of perovskite film are improved.Finally,the performance of PPDs devices can be improved.(3)The high-performance PPDs was prepared by introducing the additive PBDB-T:IHIC as bulk heterojunction(BHJ)into the perovskite active layer.The effect of PBDB-T:IHIC with different concentration as additive on device performance was studied.The results show that proper concentration of PBDB-T:IHIC can passivate the defects of perovskite films,thus reducing the dark current of devices and improving device performance.Compared to the control group,the highest D*of device reached2.61×10¹² Jones and increased two times,the dark current decreased by nearly four times.In summary,in this paper,the additive P3HT:IHIC and PBDB-T:IHIC was introduced into the perovskite layer as a bulk heterojunction to prepare high-performance perovskite photodetectors,providing a new idea for the preparation of high-performance perovskite photodetectors in the future.