Preparation Of Absorber Layers In The Perovskite Solar Cell And Research Of Photovoltaic Performance

The perovskite materials composition and microstructure of light absorbing material influence strongly on the photovoltaic performance and stability, and it is significative and valuable to exploit high-performance absorb layers on both photovoltaic performance and stability. In this paper, ZnO nanorod arrays was prepared on the ZnO seed layers by hydrothermal procedure and applied for scaffold layer in perovskite solar cells, and the the influences of the growth time on the morphology, crystal structure and optical band gap of ZnO nanorod arrays, also the corresponding CH3NH3PbI3 filling and photovoltaic performance were investigated. WO3 nanoarrays were prepared by hydrothermal procedure and applied for scaffold layer in perovskite solar cells, the influences of the composition growth solution and annealed treatment on the morphology, crystal structure and optical absorption of WO3 nanoarrays arrays, also the corresponding CH3NH3PbI3 filling and photovoltaic performance were systematically analyzed. The precursor solution of PbICl was prepared by adding PbCl2 powder into the DMF solution of PbI2 at room temperature with the molar ratio of PbCl1 and PbI2 at 1:1, and the resulted PbICl thin films were convert to CH3NH3PbI3-xClx thin film by the CH3NH3I treatment. The influence of the PbICl solution concentration on the morphology, crystal structure, optical absorption of PbICl and CH3NH3PbI3-xClx thin film and photovoltaic performance of perovskite solar cell.The results revealed that the resulted ZnO thin film showed the ordered arrays and were perpendicular to FTO substrate; the diameters of ZnO nanorods increased from 53 run to 75 nm,94 nm and the nanorod length increased from 517 nm to 656 nm,1040 nm with the growth time of 40 min,60 min and 80 min, and the corresponding perovskite solar cell achieved the photoelectric conversion efficiency of 6.72%,5.55% and 3.38%, respectively. Also, the perovskite displayed the good storage stability and the photoelectric conversion efficiency increased to 8.7% with the growth time of 40 min. WO3 nano-tree arrays and nano-sheet arrays were successfully prepared by hydrothermal procedure, and the perovskite solar cell get a photoelectric conversion efficiency of 4.96% with unannealed WO3 nano-tree arrays,which was the highest photoelectric conversion efficiency using pure WO3 as compact layer and scaffold layer in perovskite solar cell. The solubility of PbCl2 in DMF is dramatically improved by the formation of PbICl, and the precursor solutions of PbICl with the concentration of 0.8 mol·L-1,1.0 mol·L-1,1.2 mol·L-1 and 1.4 mol·L-1 have been obtained. The thickness of corresponding PbICl thin films with low crystallinity and porous morphology were 13nm、141nm、162nm and 184nm, and the thickness of CE3NH3PbI3-xClx thin film were 212nm,297nm,367nm and 431nm. Cl doping in CH3NH3PbI3-xClx thin film have been successfully achieved by CH3NH3I vapor-assisted solution process with PbICl precursor solution, and the Cl content in CH3NH3PbI3-xClx thin film based on 0.8 mol·L-1 PbICl solution was highest,and the corresponding perovskite solar cell gave a highest photoelectric conversion efficiency of 11.11% with Voc of 0.93 V, Jsc of 17.31 mA·cm-2 and FF of 0.69. The perovskite solar cell based on 1.0 mol·L-1,1.2 mol·L-1 and 1.4 mol·L-1 PbICl solution achieved the photoelectric conversion efficiency of 10.21%,7.29% and 6.85%, respectively.