| Perovskite solar cells(PSCs)have attracted a wide attention in the energy field due to their high power conversion efficiency(PCE)since 2009.So,many universities have set up special research groups for studying PSCs.So far,the highest PCE of perovskite solar cells has achieved 23.3%.With the deepening of research,the drawbacks of perovskite solar cells have gradually attracted tremendous attention such as high cost,environmental pollution,and poor stability in the air,which need to be solved.In this paper,NiO,used as a hole transport material(HTM)instead of the small molecule organic spiro-OMeTAD,was fabricated by different synthetic methods.In order to achieve low cost,high stability,and environmentally-friendly PSCs.The main work exhibit four aspects as following:NiO,prepared by a hydrothermal method,were coated with the mixture of graphene oxide(GO)and reduced graphene oxide(rGO)to improve the electrical conductivity.It was found that PSCs with rGO/GO@NiO film,prepared via a spray coating method,asa hole transport layer achieved 1.44% power conversion efficiency.Although the PCE of PSCs with rGO/GO@NiO film is largely lower than the traditional PSCs(15%),it can reduce cost and enhance the stability of PSCs in the air.The mixture of Ni and NiO(Ni@NiO)were fabricated via hydrothermal and oleic acid treating process.The holes transfer rate of Ni@NiO films was superior than pure NiO films as hole transport layer,enhancing the short-circuit current density.Moreover,PCE of PSCs with treating NiO(1.04%)was higher than that of untreated.The organic material coating NiO(O@NiO)were prepared by a hot-injection method,which has good dispersibility and stability in an organic solvent such as isopropyl alcohol or chlorobenzene.O@NiO powder were dislodged organic material after the ozone(O3)treating and the hexanethiol treating process.Obviously,it was found that O@NiO with ozone(O3)treating and the hexanethiol treating process achieved 4.5% PCE.The NiO,synthesized by the chemical precipitation method,can be uniformly and stably dispersed in isopropanol and chlorobenzene solution without any treatment.Then,NiO film,as a hole transporting layer,were prepared by the spraying method.The PCE of PSCs with the above films is low due to pores in NiO films.Moreover,we also doped spiro-OMeTAD into NiO films as a fill-in material,increasing the PCE from 1.02% to 10.95%.It can be proved that spiro-OMeTAD interacts with NiO,which effectively enhances the power conversion efficiency and reduces cost. |
