Study On Preparation Of P-I-N Type Perovskite Solar Cells By Solution Method

In recent years, the global population has increased rapidly. Industrial development is getting faster and faster with more and more energy consumption. For the long term sustainable development, the demand for renewable energy has become more and more intense. Because of perovskite (ABX3, A=CH3NH3, B=Pb, Sn, and X=Cl, Br, I) solar cells’outstanding advantages:(1) light capture rate is very high. (2) Main raw material is cheap and the storage is sufficient. (3) It can be prepared by the low temperature spin coating technology. (4) After absorption of light, the electron is easy to produce and the energy consumption is low, perovskite solar cells gradually attract people’s attention and develop rapidly. Because of being sensitive to oxygen and moisture, easily changing crystal structure, People have put forward higher requirements for the preparation process and structure optimization of perovskite solar cells.Aiming at the above problems, this paper mainly studies the efficiency of the solution system of perovskite solar cells and the preparation of the charge transport layer on the solar cell. The specific work is as follows:(1) Improving the surface morphology of Perovskite Thin Films is the main way to improve the PCE of the devices. In the literature, the method of adding solid additives in precursor solution is usually adopted, such as NH4Cl, CH3NH3Cl, etc. We found that adding proper amount of PbCl2 in the perovskite precursor solution can also achieve the goal of improving the efficiency basing on the two step method of preparing perovskite solar cells. With the increase of the amount of PbCl2, the efficiency of the device has been significantly improved. I finally found that the optimal ratio of PbCl2:Pbl2 is 1:1 (molar ratio), the efficiency reached 9.5%.(2) Application of GBL and DMSO mixed solvents. The solvent in the preparation of perovskite solar cell is essential for the control of riding on the formation and morphology of perovskite layer. In view of the fact that DMSO and Pbl2 have a strong interaction, I mix DMSO and GBL in a certain proportion in the process of preparing perovskite cell by one step spin coating method based on MAPbl3 and finally found that DMSO can improve the morphology of perovskite well.(3) Attempting different annealing temperature. About the research of perovskite solar cell, the two step spin coating method is usually used in the previous literature in which lead halide and methyl iodide are spin coated on the charge transport layer and then annealed. However, the appearance of one step spin coating method not only greatly simplifies the experimental process, but also makes the perovskite film more complete by taking control of the excess ammonium of lead halide and methyl iodide in the maximum extent. Battery efficiency has better performance by one step spin coating method. So it is very important to study the different annealing temperature for perovskite solar cells prepared by one step spin coating method.