The Crystal Structure And Photoelectric Performance Of Organic-Inorganic Hybird Perovskite For Solar Cells

It has become an important topic for researchers from all over the world making use of solar energy to deal with the energy crisis and envcfgironmental problems, since coal, petroleum, natural gas and other non-renewable energy sources are exhausting. Organicinorganic hybrid perovskite solar cells had obtained a swift and violent development due to its low temperature fabricating, high stability and low cost, just a few years after it was found since 2009. The photoelectric conversion efficiency of perovskite solar cells has increased from 3.8% to 22.1% since then. As the absorbing materials of solar cells the organic-inorganic hybrid perovskite membrane do great influence in the performance of photoelectric conversion efficiency of solar cell. Therefore, it is necessary to do the research on the crystal structure and photoelectric properties of it.In this article, we explored the stability structures of the organic-inorganic hybrid perovskite CH3NH3 Pb I3 and also established the structures of CH3NH3 Pb I3-xClx(x=1~3) that doped with Cl. Also, we got the electric structures and photoelectric properties of the different systems of perovskite through the CASTEP program of the software Materials Studio.According to the results, we found that the photoelectric performance of the CH3NH3PbI3-xClx system is superior to the CH3NH3PbX3 system, of which the CH3NH3PbI2 Cl perovskite crystal structure has a higher carriers concentration, relatively small band gap and wide range of light absorption,so that it may be a most suitable material as light absorption layer of solar cells.According to the result of TG-DTA measurement, our approach involves casting a hot mixture of CH3NH3 Cl and PbI2(?) solution onto a sbustrate maintained at a temperature of 170? and subsequently spin-coated to obtain a uniform film.And then post-annealed fo 10 min in the drying oven at 120?.The most interesting is that the Xray diffraction pattern shows sharp and strong perovskite peaks for the hot-casted film at 14.8° and 15.2° which is different with other papers' results. After testing and characterization, we found the preparation of the perovskite membrane structure and properties can fitting well with the results of first principles calculation.Then using the finite element software COMSOL to build a hole-transporting free planar heterojunction device modeling of organic-inorganic hybrid perovskite solar cells and do the numerical analysis on it.Simulated under monochromatic light irradiation and sunlight irradiation, testing the photoelectric response of different systems and thickness of perovskite absorption layers in the divices. Results show that choosing CH3NH3PbI2 Cl as the light absorption layer with the 300 nm thickness may get the highest photoelectric conversion efficiency of the planar heterojunction structure of organic-inorganic hybrid perovskite solar cell.