Growth And Characterization Of Organic-Inorganic Hybird Perovskite CH₃NH₃PbX₃?X=Cl,Br,I? Single Crystals

The organic-inorganic hybrid perovskite CH₃NH₃PbX₃?X=Cl,Br,I?has emerged as a strong competitor in photovoltaic and general optoelectronic applications duo to its superior characteristics including high absorption coefficient,long carrier lifetime and high balanced hole-electron mobility,etc.In the field of photovoltaic,the polycrystalline perovskite CH3NH3PbX3 thin film has obtained the high conversion efficiency compared with monocrystalline silicon in the laboratory.The crystal CH3NH3PbX3 has also been used as photodetector and laser,etc.As a novel material,its photoelectric properties and semiconductor properties need to be further studied.Therefore,the growth of high-quality single crystal is an important way to study the properties of perovskite CH₃NH₃PbX₃.In this paper,CH₃NH₃PbX₃ single crystals have been grown by solution method.The continuous growth of the crystal has realized by continuous solute feeding.The steady-state temperature field was established to obtain the optimum technological parameters of crystal growth.Using in situ growth method with fixed seed crystals can avoid the introduction of pollution effectively.Using this experimental set-up,the single crystals with centimeter-level have been obtained successfully.Based on the crystal growth experiments,numerical simulation of the temperature field in the growth vessel was performed.It was found that the heating method,the diameter of the seed suspension wire and the position of the feeding port of the growth vessel had certain influence on the temperature field in the growth vessel.According to the simulation results,the experimental set-up has been improved and the satisfactory experimental results have been obtained.Single crystal growth experiments were conducted on the improved experimental set-up.The effects of different solvents,seed types and solution super saturation on the quality of single crystal growth have been analyzed,and the optimum process parameters for the growth of CH₃NH₃PbX₃ single crystals have been determined.The physical characteristics of the as-grown CH₃NH₃PbX₃ single crystals have been measured.The structure of single crystals were complete and the performance indicators were at a comparable level with the reported.The high carrier concentration and migration rates show that these crystals have potential application as semiconductor materials.