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Although perovskite solar cells have achieved great development in the device performance, the device stability is still a crucial issue hinder the further development. The ion migration is a main reason for the poor stability of the perovskite solar cells. Here, we use a cross-linking material, polydimethylsiloxane (PDMS) to dope the perovskite layer to improve the operational stability. We systematically studied the effect of curing agent content in PDMS on the device performance and stability. The characterization of perovskite film indicates that PDMS primarily doped in the perovskite layer and as well as enriched at the surface of perovskite film. Doping of PDMS promoted the crystallization of perovskite phase, leading to increase of short circuit density (JSC) and fill factor (FF) of the solar cells. In addition, PDMS doping improved the operational stability of device due to the suppressing the migration of iodide ions during aging. Moreover, the higher content of curing agents used in PDMS, the better stability of the devices. This work indicates PDMS doping the perovskite layer with a suitable content of curing agent can produce a better operational stability of the perovskite solar cells.

Silver nanowires (Ag NWs) network is an excellent candidate as flexible transparent electrode applying in flexible perovskite solar cells, owing to their excellent electrical and optical properties. However, several problems including large surface roughness, chemical reaction between Ag and perovskite precursor, and migration of Ag limited the application in high performance perovskite solar cells. Aiming to solve these problems, the composite electrode combining the spray coated Ag nanowires and the low-temperature sol-gel zinc oxide was developed in this work. The optimized concentration and annealing temperature of sol-gel ZnO were 0.45 M and 150 °C. The introduction of zinc oxide with suitable concentration caused slight impact on the transmittance and sheet resistant of transparent composite electrode, and promoted mechanical and chemical stability in air relative to the pristine Ag NWs electrode. The use of the composite flexible electrode could decrease the surface roughness of the Ag NWs electrode, passivate the reaction of perovskite and silver electrode, and prevent the migration of Ag. As a consequence, the performance of the flexible device significantly improved from 9.51% to 13.12%. Under the AM 1.5G constant illumination, the optimization device has a remarkably improved stability than pristine device. This study demonstrates that spray Ag NWs as bottom electrode is suitable for flexible perovskite solar cells. Meanwhile, it's an effective method using sol-gel ZnO to construct composite electrode to promote the device performance and stability.

Three kinds of nanostructured alumina coatings were prepared by air plasma spraying (APS). The microstructure of these coatings was characterized by SEM and X-ray diffraction (XRD). The surface roughness, porosity and microhardness of as-sprayed coatings were measured. The results indicated that the smaller the size of starting powder was, the better properties the coating possessed. The differences among phase analysis of these as-sprayed coatings could explain it.