Preparation And Optoelectronic Properties Of Inorganic Perovskite Solar Cells With High-Efficiency

Since 2009,the efficiency of perovskite solar cells(PSCs)has increased from 3.8%to 22.7%,which has attracted great attention.However,the commercial application of PSCs is hindered by the drawback of the organic-inorganic hybrid perovskite materials,such as thermal degradation,photodegradation,and temperature instability due to the presence of organic cations,which leads to a decrease in the power conversion efficiency(PCE)of the PSCs.On the other hand,all-inorganic perovskite materials,by substituting organic cations with inorganic ions,have greatly improved thermal stability and light stability,and are expected to be more advantageous to the photoactive layer of industrially produced solar cells.Inorganic lead halide perovskite materials have been widely studied in recent years.The cubic phase CsPbI3 has a suitable bandgap(1.7eV)and the absorption edge is near 730 nm,which is the preferred material for the photoactive layer of inorganic PSCs.However,it is difficult to form a stable CsPbI3 cubic phase at room temperature.Therefore,the preparation of all-inorganic perovskite films with high quality and excellent performance still requires systematic exploration.The explore for the convenient and efficient thin film preparation methods is extremely important for the research and development of all-inorganic PSCs.In this paper,a series of investigations were carried out on the preparation and performance optimization of all inorganic CsPbBr3-xIx PSCs.The main research experiments and results are as follows:Firstly,In order to produce high quality CsPbBr3-xIx thin film,the convention one-step spin coating method and anti-solvent induced crystallization method were used to systematically explore the influence of the preparation method of CsPbBr3-xIx thin films on the surface coverage,morphology,density,crystallinity,and light absorption.In addition,the influence of anti-solvent treatment on the efficiency of the inorganic PSCs was investigated.The results showed that the efficiency of the anti-solvent-treated all-inorganic PSCs was increased from the previous 4.51%to 8.60%.Secondly,Through the optical bandgap engineering,CsPbBrI2 with high absorption efficiency was obtained.SnO2 prepared at low temperature was effective on the energy band adjustment and the improvement of change transport.Solar cell with high PCE of 11.21%was achieved.Finally,in order to reduce the cost of PSCs and increase the stability of the device,the carbon electrode was used to replace the expensive Spiro-OMeTAD and the gold electrode,and CsPbBrI2 solar cell with carbon electrode was investigated in detail.