Growth Of Thin Perovskite Single Crystal Via Ultrasonic Method And Application For Solar Cells

In today’s world,human being are still facing two major challenges:energy shortage and envioronmental pollution.Compared with traditional energy sources,solar energy is an ideal renewable energy.However,there are still some problems with traditional photovoltaic materials such as high manufacturing cost and environmental pollution,meanwhile,perovskite solar cells has received widespread attention due to its low cost and excellent photoelectric conversion efficiency.High efficiency of perovskite solar cells is due to its high light absorption,long carrier mobility and carrier lifetime.However,in order to commercialize the research as soon as possible,there are still some problems to be solved,such as improving the stability and efficiency of batteries.Due to the advantages of single crystal perovskite in these aspects,such as no crystal boundary,few defects and high stability,compared with perovskite films and nanowires,perovskite single crystals have a wider application prospect.However,in practice,it is difficult to grow large-size perovskite single crystals by using the space-confinement method alone.In this paper,we try to combine the ultrasonic method with the space-confinement method and adopt the inverse temperature crystallization method,the main work of this paper are as follows:a)the growth of MAPbBr₃thin perovskite single crystals by ultrasonic method combined with space-confinement methodPerovskite single crystal has great advantages as photoelectric material,but in the process of growing thin perovskite single crystals using traditional space-confinement method,a large number of perovskite seed crystals will inevitably grow when perovskite precursor solution is heated,therefore,it is difficult to grow large size single crystal and sometimes it will grow up to be polycrystals or twin crystals.Fluorosilane are easy to form polyorganosiloxane coatings with low surface energy,in this work,first,a solution of perovskite precursor is sandwiched between two hydrophobic glass sheets to create a finite space in which crystal growth in one direction is inhibited,then one certain single perovskite seed crystal was induced away from other perovskite seed crystals by ultrasonic wave,so as to avoid its combination with other seed crystals and obtain the maximum growth space in the limited container.At the same time,perovskite crystal can be grown in proper concentration and temperature by continuously replenishing the precursor solution of perovskite and keeping the temperature.Because of the limited space,one crystal can only grow in transverse direction,so large-sized thin perovskite crystal can be grown.Thin perovskite crystals grown by this method not only have controllable thickness and large size,but also have smooth morphology and superior properties.b)the preparation of perovskite solar cells using MAPbBr₃thin single crystal Although perovskite has been widely studied because of its excellent properties,most of the current studies are still focused on polycrystalline perovskite films,which makes the problem of poor stability of perovskite films especially prominent,single crystal perovskite is superior to perovskite thin films in thermal stability,and it also has strong advantage and feasibility in preparing solar cells due to its non-crystal boundary and lack of defects.In this work,thin perovskite crystals with excellent properties were grown by the space-confinement method.Au was evaporated at one end of the single crystal,C₆₀and BCP were evaporated at the other end,and the mask was covered at the boundary of the two parts,Au was evaporated at the top as the cathode,the single crystal solar cells made by this method have good efficiency and better stability than perovskite thin film detectors,and have a broad prospect in the application of optoelectronic devices.With the gradual depletion of energy,solar cells made of thin single crystal perovskite is expected to break through the defects of non-renewable energy and traditional photovoltaic materials and become a new driving force for industrial development.