The Study Of NiO As Hole Tansport Material In Carbon Counter Electrode Based Perovskite Solar Cells

As an effective way using clean energy, solar photovoltaics brings hopes to alleviate serious problems of energy and environment. As a new generation of photovoltaic technique, organic-inorganic hybrid halide perovskite solar cell possesses both significantly higher energy conversion efficiencies and low fabrication costs. It has become one of the most attractive research area.Counter electrodes and hole transport layer are two important parts of PVSC. However, the expensive metal, such as Au, is generally choosed as counter electrode materials in perovskite solar cell. Metal based counter electrode also requires complex vacuμm evaporation process, which leads to high request of equipment and severely preparation environment. Spiro-OMETAD, one kind of small molecule material, is commonly used as hole-transporting materials, but its high cost and low physical and chemical stability is still an obstruction for the practical application of PVSC.To solve above problems, we select mesoporous carbon as the counter electrode, inorganic NiO as hole-transporting material for PVSC. The carbon electrode is composed of inorganic graphite and carbon black powder materials, fabricated by simple screen printing method. Furthermore, carbon itself has hydrophobic property, which make carbon counter electrode based PVSC possess advantages of high stability and compatibility of large-scale production; Inorganic Ni O is also an attractive materials, which have the advantage of low cost, high stability and corrosion resistance.In this paper we have sequentially studied two meso-structureed PVSC: TiO2/NiO/C(perovskite), TiO2/ZrO2/NiO/C(perovskite). The study of the first device has proved that the replacement of insulator ZrO2 with p type NiO can improve the charge collection and transport behavior, thus improved the photoelectric conversion efficiency. The study of the second device, in which NiO nanosheets with high crystallinity was used as HTM, showed further improved overall performance. We concluded that NiO nanosheets can collect and transport holes more efficiently than NiO nanoparticals.