Research On Interface Modification And Low Light Intensity Performance Of Printable Mesoscopic Perovskite Solar Cells

Since the organic-inorganic hybrid perovskite was used in solar cells as a light absorbing material,the performance of devices has improved continuously,and thus perovskite solar cells(PSCs)have attracted the attention of researchers from all over the world.Among various device structures,printable mesoscopic PSCs based on the triple-mesoscopic structure(Ti O2/Zr O2/Carbon)have gradually formed a featured research topic due to its cheap raw materials,simple fabrication process and high stability.In this paper,based on the fabrication processes and structural characteristics of printable mesoscopic PSCs,the performance of the device is improved through interface modification,and the potential for performances and applications of this type of devices under low-intensity illumination conditions are explored.The details are as follows:(1)Based on the typical material system of printable mesoscopic PSCs,small area devices(0.1 cm²)with open-circuit voltage(VOC)of 895.35±6.57 m V,short-circuit current(JSC)of 23.64±0.17 m A cm^-2,filling factor(FF)of 0.67±0.01 and PCE of 14.16±0.19%were fabricated.Based on the structure of triple-mesoscopic layer and the filling of perovskite absorbers in the mesoporous scaffold,the causes for the low VOC are analyzed and discussed.(2)A post-treatment method for modifying the interface of perovskite/mesoporous carbon electrode was proposed.Through VOx post-treatment,the VOC and PCE of the device are effectively improved,for which the VOC is increased by 30.13±5.19 m V on average,the PCE is increased by 0.89±0.16%on average,and the highest PCE of the device is up to 15.77%.The results show that the VOx post-treatment with high work function can effectively improve the charge transfer at the interface of perovskite/mesoporous carbon electrode,and reduce the potential loss of the devices.(3)The performance of printable mesoscopic PSC mini-modules(10×10 cm²)under low-intensity illumination is studied.Three traditional solar cells which have been commercialized are also characterized for comparison.The results show that the printable mesoscopic PSC mini-modules begin to show a certain PCE advantage when the light intensity is lower than 0.3 Sun(300 W m^-2).When the light intensity is further reduced to the standard indoor low light level(1000 lux,?3 W m^-2),the PCE of printable mesoscopic PSC mini-module is increased to 19.83%.