Study On Perovskite Solar Cell Based On Tin Oxide Electron Transport Layer

The conversion of solar energy into electrical energy is the most effective way to solve the energy crisis since the solar energy is inexhaustible.And the perovskite solar cells,which have been widely concerned by researchers,have higher photoelectric conversion efficiency and simple manufacturing process.The perovskite materials commonly used as the absorption layer of perovskite solar cells have many characteristics such as high absorption coefficient,long carrier diffusion length,and suitable band ganp.Since the Miyasaka group produced the first perovskite solar cell with a photoelectric conversion efficiency of 3.8%in 2009,the photoelectric conversion efficiency of the perovskite solar cell has reached the certified photoelectric conversion efficiency of 25.2%.The electron transport layer mainly plays the role of transporting electrons and blocking holes in the perovskite solar cell,and is an indispensable component of the perovskite solar cell.The commonly used electron transport layer TiO2 requires a higher annealing temperature,which increases its preparation cost,and limits its application to flexible substrates.Although the optimized TiO2 electron transport layer does not require a too high annealing temperature,the oxygen vacancies in the TiO2 electron transport layer and the accelerated decomposition of the perovskite layer under ultraviolet irradiation caused by TiO2 may affect the performance and stability of the device.Under normal circumstances,the electron mobility of perovskite materials will be different from the electron mobility of TiO2,which will lead to the imbalance of electron transport in perovskite solar cells,which will affect the performance of the device.SnO2 and TiO2 have similar energy band positions,crystal structure and physical properties,while SnO2 has higher electron mobility,which can increase charge transfer more effectively and reduce charge loss.At the same time,the energy band of SnO2 is better than that of TiO2.The position of the energy band will increase the charge extraction and hole blocking ability.The crystallization temperature of SnO2 is lower than that of TiO2.The crystallization temperature of SnO2 is lower than that of TiO2.Therefore,in the field of flexibility and large-area applications,SnO2 has a better application prospect.At the same time,SnO2 has better chemical stability and better anti-reflection ability.In this paper,two preparation methods of SnO2 electron transport layer are studied,(one kind of the electron transport layer is prepared by hydrolysis and oxidation of SnCl2,and the onther electron transport layer is prepared by using SnO2 colloid).The preparation process is adjusted and used as the electron transport layer of perovskite solar cells separately.And the effect of two methods on the performance of perovskite solar cells are studied.Then the two methods were combined to prepare the SnO2 electron transport layer,and the obtained SnO2 electron transport layer was tested by PL with stronger electron extraction among the three kinds of SnO2 electron transport layer.The organic-inorganic hybrid perovskite solar cell device prepared on the layer has a better performance,and the highest photoelectric conversion efficiency of the(FAPbI3)0.83(MAPbBr3)0.17 device can reach 16.32%.Then,under the inorganic perovskite solar cell system,the SnO2 electron transport layer fabricated by SnO2 colloid is more suitable than the onther two,and by optimizing the doping of the CsPbI3 perovskite light-absorbing layer,the photoelectric conversion efficiency of the optimal device reached 13.22%.