Study On The Growth Of MAPbI₃ Columnar Single Crystal And Its Photodetector

With the continuous progress of science and technology,our life is increasingly informationized.Photoelectric detection technology,as a technology that can convert optical signals into electrical signals instantaneously,has attracted people's attention.It can be widely used in all walks of life.Because of its wide range of practical life,there will be more and more people interested in the study of photoelectric detector.In the past,Si,GaN,GaAs and other inorganic materials have been most widely used in detectors.At present,the manufacturing technology and product performance of this kind of photodetectors have been quite mature and widely used.In recent years,perovskite has attracted the attention of a large number of scholars due to its inherent properties such as high carrier mobility,large absorption coefficient,wide spectral absorption range and low defect density,and has become a hot material for the study of photodetectors.As far as perovskite single crystal is concerned,in previous reports,some scholars have prepared large single crystal of organo-inorganic hybrid perovskite for photodetection research,but the preparation process is characterized by high drug consumption,low utilization rate and long time.Lead in this article,therefore,methylamine iodine as the research object?below one amine lead iodine are expressed in MAPb I₃?,with perovskite crystal material itself superior characteristics as a starting point,around the perovskite crystal in the process of growth,such as temperature,concentration,time exploring different influencing factors,and in determining the growth condition of the lower limit of single crystal growing light detection performance study,the main work is as follows:1.The appropriate concentration of the seed precipitate was preliminarily explored by inversion crystallization method.It was found that the concentration range of suitable seed precipitation was 1.32?1.5M,but the number and size of seed particles were different at different concentrations.The appropriate concentration can be selected according to the experimental purpose in the subsequent experiments.2.The optimum temperature,concentration and time of crystal growth with seed induction were analyzed by inversion crystallization method.It was concluded that the optimum temperature for seed growth was 100?,the optimum concentration was 1.3M,and the optimum growth time was 6h.Under these growing conditions,drugs can be used to a greater extent without wasting extra time.3.Combined with inversion crystallization and seed induction,large block MAPbI₃ single crystal was prepared more quickly and efficiently according to the growth conditions obtained by analysis.4.Combined with inversion crystallization method,seed induction method and restricted growth method,columnar MAPb I₃ single crystal was rapidly and efficiently grown,and the electrode was prepared and assembled into a light detector to study its light detection performance.It is found that the columnar MAPb I₃ single crystal has the strongest response to the 675nm light source,with a response of 76.23A·W^-1,an external quantum efficiency of 1.4×10⁴%,and a detection degree of 1.93×10¹³Jones.When the wavelength of 405nm laser light source is provided,the maximum spectral response is 16.03A·W^-1,the external quantum efficiency is 4121.69%,and the detection degree is 4.18×10¹¹Jones.To sum up,focusing on the exploration of temperature,concentration,time and other conditions in the growth of MAPbI₃ single crystal,inversion crystallization method and seed induction method are used in this paper to rapidly and efficiently grow large quantities of MAPbI₃ single crystal,and further restrict the growth to columnar MAPbI₃ single crystal.Then,the application of MAPbI₃ single crystal in optical detection direction is studied.