Investigation And Optimization Of The New Hole Transporting Material In Migh Performance Planar Perovskite Solar Cells

Recently,the solar photovoltaic industry grows rapidly because of the deterioration of enviroment and the increased greenhouse effect.Perovskite solar cells（PSCs）as next-generation photovoltaic devices received much attention due to their good light absorption and high power conversion effciency（PCE）.Meanwhile there are some factors limit the development of the PSCs,such as the poor stability perofomance in ambient air and lack of effecitive c ommercial processed method.The hole transport material（HTM）plays an important role in the PSCs.By modifying the HTM,we can improve the PCE and stability performance of PSCs.The researchers commonly use the PEDOT:PSS as the HTL in the inverted planar hetrojunction PSCs.Therefore we use PDA:PEDOT:LS and solution-combustion-based NiO_x to replace the PEDOT:PSS and test the new film as well as the new-film-based devices by using amounts of characterization methods.The main contents are as follows:1)As for modifying the HTM by using organic materials,we use the PDA:PEDOT:LS which has a lower acidity and hydrophilicity to replace the PEDOT:PSS.We use various characterizations to analyze the morphology,light absorption,hydrophilicity and waterpoofness of the PDA:PEDOT:LS film.Also we test the performance of PDA:PEDOT:LS and PEDOT:PSS based device,certifying the PDA:PEDOT:LS based device is more reliable and has a higher PCE.2)As for modifying the HTM by using inorganic materials,we use the solution-combustion-based NiOx to repalce the PEDOT:PSS.By controlling the annealing temperature and annealing time,we successfully find the optimal processed condition of solution-combustion method.Finally we develops a PSC whose V_oc is 1.12V,J_sc is 23.7 mA/cm²,FF is 0.76 and PCE exceeds 20%by using a modified two-step prepared MA1-y FA_y PbI3-xCl_x perovskite.3)Compare to the sol-gel NiO_x based devices and PEDOT:PSS based devices,the solution-combustion NiOx based device shows a significantly improvement.Thus w e use various characterization methods to analyze the different methods-processed NiO_x films and the corresponding devices.The results provide evidence of better film quality,enhanced charge tanrsport and extraction,and suppressed charge recombination.4)We study the stability performance of PDA:PEDOT:LS based PCSs and solution-combustion NiO_x based PCSs in the ambient air with RH<30%for 1 month.They all exhibit a remarkble PCE stability,the PDA:PEDOT:LS based PCSs’PCE is almost unchanged and PCE of the device with NiO_x HTL based on combustion route retains 93.7%of its initial value,compared to 50%PCE for PEDOT:PSS based devices.