Preparation method of highly stable lead-based organic-inorganic hybrid perovskite nano sheet

Abstract

The invention provides a preparation method of a lead-based organic-inorganic hybrid perovskite nanosheet, the lead-based organic-inorganic hybrid perovskite nanosheet is prepared by a two-step method, and comprises the following steps: 1, dripping supersaturated lead halide aqueous solution onto a substrate to prepare a lead halide substrate; and 2, heating an organic precursor to a gas phase state for fully contacting and reacting with the lead halide substrate to obtain a lead-based organic-inorganic hybrid perovskite nano sheet. In the gas phase method, hydrophobically modified piperazineis added to the organic precursor for treating lead halide. The wetting angle of the perovskite nanosheet increases obviously, which indicates that the water resistance of the perovskite nanosheet isimproved. Aging tests prove that perovskite can keep stable for a long time under high temperature and high humidity environment, and the perovskite can be prepared into a solar cell with good photoelectric efficiency. The lead-based organic-inorganic hybrid perovskite nanosheet provided by the preparation method has excellent comprehensive performance, can simultaneously have good photoelectric efficiency and stability, and has good market promotion prospects.

Description

technical field [0001] The invention relates to the technical field of perovskite preparation, in particular to a preparation method of lead-based organic-inorganic hybrid perovskite nanosheets. Background technique [0002] Perovskite is a material class defined by a specific crystal structure, the general chemical formula is AMX 3 or A 2 MX 4 , A, M, and X sites can obtain various perovskite materials by selecting different components. Among the M site elements, lead and tin are generally used in solar cells. These raw materials are much cheaper than crystalline silicon and can be sprayed onto glass without the need for elaborate assembly in a clean room. [0003] Due to the special structure of perovskite materials, it has potential application prospects in high-temperature catalysis and photocatalysis. The research on perovskite structure type materials at home and abroad mainly focuses on the material structure. Relatively small. In addition to crystalline silicon,...

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Problems solved by technology

[0006] There are certain problems in the perovskite synthesis methods mentioned above. Due to the poor chemical stability of perovskite itself, the process of solution growth will inevitably introduce defects and impurities, and the selection of organic solvents is complicated and easy to pollute the environment. The deposition rate of the deposition method is low, and the equipment requirements are very strict, it is difficult to carry out large-scale preparation, and the pollution caused by Pb to the environment cannot be avoided. In addition, the gas phase doping method has great limitations on the selection of perovskite organic precursors. For doped CH 3 NH 3 I(MAI) etc. can be inserted into lead halide nanosheet PbX 6 Smaller organic molecules with short carbon chains in the octahedral gap are more suitable, while organic molecules with long carbon chains generally use solution casting or crystallization to grow two-dimensional perovskites, which require many types of solvents and the process is complicated. And the solution growth process is easy to introduce grain boundaries

[0007] There are also perovskite high-temperature solid-phase method, perovskite sol-gel method, perovskite precipitation method, high-energy ball milling method, supercritical drying method, microemulsion method and self-propagating high-temperature combustion synthesis method, etc., but these methods either Obtained perovskite products are easy to agglomerate particles, and the particle size distribution is not uniform enough, so that the photovoltaic efficiency of solar cells is low, or special equipment and instruments are required, the operation is complicated, and the cost is high

[0008] In addition, although the performance is excellent, the two shortcomings of lead-based organic-inorganic hybrid perovskite solar cells: long-term instability and heavy element lead (Pb) have become the biggest bottleneck for its practical application.

However, this method still does not avoid the disadvantages of the general solvent method to prepare perovskite, that is, the introduction of defects and impurities cannot be avoided. This may be because the method only gives the yield of perovskite, which has a great impact on its stability and performance as a battery. no reason mentioned

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