Preparation Of Y-Doped TiO₂ Compact Layer And Nanorod Arrays And Study On Photovoltaic Performance Of Perovskite Solar Cells

Organic-inorganic hybrid perovskite solar cells have attracted much scientific interest in the field of solar energy harvesting and conversion owing to their simple structure and excellent properties.Perovskite solar cells are mainly composed of FTO,TiO₂ compact layer,TiO₂ scaffold layer,perovskite thin films,hole transport layer and counter electrode,in which the TiO₂ compact layer and the scaffold layer have a great enfluence on the photovoltaic properties.?1?Y-doped TiO₂ compact layer was prepared by hydrolysis-pyrolysis methods as electron transport layer,we studied the effects of Y/Ti molar ratio in isopropanol acid solution on the chemical composition,microstructure,crystal phase and optical absorption of TiO₂ compact layer,comparison of the photovoltaic properties of the un-doping and Y-doped TiO₂ compact layer of perovskite solar cells,the charge separation and recombination at the interface of TiO₂/perovskite can be investigated by analyzing the corresponding PL and EIS data.The results revealed that the different molar ratio of Y/Ti in acidic solution of isopropanol has no obvious effect on the crystal phase and optical absorption of TiO₂ compact layer,the molar ratio of 5%Y-doped TiO₂compact layer with smaller size and the surface was smooth and compact,the PCE of the corresponding un-doping and Y-doped TiO₂ compact layer of planar perovskite solar cells were 14.05%and 15.52%,respectively.The results of PL and EIS showed that Y-doping can improve the electron transport in TiO₂ and the charge separation at the interface of TiO₂/perovskite..?2?Y-doped TiO₂ nanorods array was successfully prepared by hydrothermal methods.The Y-doped TiO₂ nanorod arrays with Y/Ti molar ratio of 0%,3%and 5%in hydrothermal solution were studied,the photoelectric conversion efficiency?PCE?of the corresponding TiO₂ nanorod arrays perovskite solar cells were compared,the charge separation and recombination at the interface of TiO₂/perovskite can be investigated by analyzing the corresponding PL and EIS data.The microstructure,crystal phase and optical absorption of TiO₂ nanorod arrays with Y/Ti molar ratio of 0%,3%and 5%in hydrothermal growth solution were compared,Y-doping can suppress the radial growth and further enhance the areal density of TiO₂ nanorod arrays,and exhibited the higher crystallinity,but the absorption onsets of the three TiO₂ nanorod arrays had no obvious impact,the PCE of corresponding champion perovskite solar cells was 18.11%,the results of PL and EIS revealed that the conductivity of TiO₂ nanorod array can be increased by Y-doping,thus the electron transport in TiO₂ nanorod array can be accelerated and the number of electrons in TiO₂ conduction band can be reduced,then increasing the V_oc and PCE.?3?We successfully assembled perovskite solar cells with Y-doped TiO₂ compact layer and Y-doped TiO₂ nanorod array as electron transport layer and scaffold layer,respectively,and the PCE of corresponding perovskite solar cells were researched,a highest PCE of 18.32%and the average PCE of 17.55±0.86%were obtained.